Multi-color golf ball

ABSTRACT

A golf ball having a single pass image printed on the outer surface having at least one core and a cover layer formed from a cast polyurethane or polyurea. The cover layer defines a first surface area portion of a first color and a second surface area portion of a single pass printed image. The single pass printed image is printed using a UV curable ink and at least one UV pinning operation to pre-cure the UV curable ink before a final UV curing operation.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No.63/066,033, filed Aug. 14, 2020, and U.S. Provisional Application No.63/067,802, filed Aug. 19, 2020, which are incorporated herein byreference in their entirety.

BACKGROUND

The playability of a golf ball may be adversely impacted by thevisibility conditions. In addition, it is useful for players to knowwhether or not a putted ball has a true roll.

SUMMARY

In one embodiments, a multi-color golf ball is disclosed.

Another embodiment is a golf ball comprising:

at least one core;

and a cover layer formed from a cast polyurethane or polyurea, whereinthe cover layer defines a first surface area portion of a first colorand a second surface area portion of a single pass printed image, and aseam upon which the single pass printed image is placed, wherein thesingle pass printed image is printed using a UV curable ink and at leastone UV pinning operation to pre-cure the UV curable ink before a finalUV curing operation.

A further embodiment is a golf ball comprising:

at least one core;

and a cover layer formed from a cast polyurethane or polyurea, whereinthe cover layer defines a first surface area portion of a first colorand a second surface area portion of at least one single pass printedimage, and a first location upon which the at least one single passprinted image is placed, wherein the at least one single pass printedimage is either rotationally or linearly printed using a UV curable inkand at least one UV pinning operation to pre-cure the UV curable inkbefore a final UV curing operation;

wherein a throw distance utilized to print the at least one single passprinted image on the cover layer is between 0 and 10 mm;

wherein an energy density of a UV pinning lamp in the UV pinningoperation is between 50 mJ/cm² to 200 mJ/cm² and at least one final UVcuring lamp used in the final UV curing operation is between 1 J/cm² and5 J/cm²;

wherein a resolution of the at least one single pass printed image isbetween 100 dpi and 1400 dpi and a volume of a single ink droplet isbetween 6 to 160 picoliters when printing the at least one single passprinted image.

An additional embodiment is a method of manufacturing comprising:

providing at least one golf ball core;

providing a cover layer formed from a cast polyurethane or polyurea,wherein the cover layer defines a first surface area portion of a firstcolor and a second surface area portion having at least one single passprinted image;

providing a first location on the cover layer upon which the at leastone single pass printed image is placed, wherein the at least one singlepass printed image is either rotationally or linearly printed using a UVcurable ink;

providing at least one UV pinning operation to pre-cure the UV curableink;

providing a final UV curing operation to cure the UV curable ink;

providing a throw distance utilized to print the at least one singlepass printed image on the cover layer is between 0 and 10 mm;

providing an energy density of a UV pinning lamp in the at least one UVpinning operation is between 50 mJ/cm² to 200 mJ/cm² and at least onefinal UV curing lamp used in the final UV curing operation is between 1J/cm² and 5 J/cm²; and

wherein a resolution of the at least one single pass printed image isbetween 100 dpi and 1400 dpi and a volume of a single ink droplet isbetween 6 to 160 picoliters when printing the at least one single passprinted image.

A further embodiment is a method comprising:

single pass printing at least one image onto a first location on a golfball cover layer, wherein the at least one single pass printed image iseither rotationally or linearly printed using a UV curable ink, whereina throw distance of between 0 and 10 mm is utilized for the single passprinting of the at least one image, a resolution of the at least onesingle pass printed image is between 100 dpi and 1400 dpi and a volumeof a single UV curable ink droplet is between 6 to 160 picoliters whenprinting the at least one single pass printed image;

subjecting the UV curable ink to a UV pinning lamp having an energydensity of between 50 mJ/cm² to 200 mJ/cm², thereby pre-curing the UVcurable ink; and

subjecting the pre-cured UV curable ink to a final UV curing lamp havingan energy density of between 1 J/cm² and 5 J/cm², thereby completingcuring the pre-cured UV curable ink.

The invention will become more apparent from the following detaileddescription, which proceeds with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a first embodiment of a multi-color golf ball.

FIGS. 2A-2C are additional embodiments of a multi-color golf ball.

FIGS. 3A-3C are further embodiments of a multi-color golf ball.

FIG. 3D is an embodiment of a multi-color golf ball aligned with aputter head.

FIG. 4 is an embodiment of a single pass printing process and image.

FIG. 5 is an embodiment of a single pass printing layout.

FIG. 6 is an embodiment of a single pass printing process and image.

FIG. 7 is an embodiment of a multiple pass printing process on a shaft.

FIG. 8 is a cross-sectional view taken along lines 8-8 in FIG. 7.

FIG. 9 is an embodiment of a single pass printing manufacturing layout.

DETAILED DESCRIPTION

Disclosed herein are useful approaches for enhancing the playability ofa golf ball.

Multi-Color Cover Layers

In one embedment disclosed herein there are multi-color golf balls inwhich the color is substantially uniformly present throughout the bulkmaterial of the cover layer. The cover layer is a cast polyurethane orpolyurea that includes at least one color additive as described indetail below. The colors (one of which may be white) cover the wholesurface area of the ball. In certain embodiments, there are only twocolors. In certain embodiments, there are only three colors.

An example of an embodiment of a golf ball with only two colors is shownin FIG. 1. The surface of the golf ball is divided into a first surfacearea portion 1 of a first color and a second surface area portion 2 of asecond color. The first surface area portion 1 and the second surfacearea portion 2 are formed by casting a first castable polyurethane orpolyurea composition that includes a first color additive and a secondcastable polyurethane or polyurea composition that includes a secondcolor additive, wherein the first color and the second color aredifferent or contrasting colors.

A seam 3 is present at an interface between the first surface areaportion 1 and the second surface area portion 2. In certain embodimentsthe seam is located where two halves of a mold come together duringmanufacturing of the golf ball. In the embodiment shown in FIG. 1 thefirst surface area portion 1 and the second surface area portion 2contact each other along the seam. In the embodiment shown in FIG. 1 thefirst surface area portion is in the shape of a hemisphere and thesecond surface area portion is in the shape of a hemisphere. Therespective colors are uniformly present over the entire surface area ofeach of 1 and 2.

In the embodiment shown in FIG. 1, the first surface area portion 1 andthe second surface area portion 2 each individually cover 50% of thetotal ball surface area (excluding any surface area occupied by images,pole stamps or pole markings).

The colors described in the embodiments herein can be contrasting colorsor any colors suitable for alignment purposes. In one embodiment, crosslinking occurs at the seam between the first and second castableurethane compositions. In yet another embodiment, crosslinking does notoccur at the seam between the first and second castable urethanecompositions.

In certain embodiments, at least one image, pole stamp, or pole marking4 is located on the seam 3 formed by the first surface area portion andthe second surface area portion. In certain embodiments, there are atleast 1, 2, 3, or 4 individual images, pole stamps and/or pole markingson the seam. As used herein, “image” refers to a physically discretedesign that has a border and includes at least two individual designelements. One of the individual design elements may be a border designelement. An “image” as used herein is not a pole stamp, pole marking,seam stamp or seam marking. Examples of images are described in U.S.application Ser. No. 16/565,283, filed Sep. 9, 2019 which isincorporated by reference in its entirety, including images anddisclosure specific to images printed on a golf ball and colorcontrasting features. Every image, pole stamp and/or pole marking on theball may be the same or there may be different images on an individualball. The image, pole stamp, or pole marking may be created on the golfball by any type of printing or application method. An illustrativemethod is ink pad printing. Another method is ink jet printing.

In certain embodiments, the surface of the golf ball may include atleast one circumferential stripe. The circumferential stripe(s) definesa continuous surface area that extends around the full circumference ofthe ball. The circumferential stripe(s) may be linear. There may be anynumber of circumferential stripes. For example, there may be 1, 2, 3, 4or 5 circumferential stripes. The uniform width of the circumferentialstripe(s) may vary. For example, the uniform width of a singlecircumferential stripe may be 0.5 mm to 35 mm, more particularly 1 mm to30 mm. In the embodiments that include three circumferential stripes,the uniform width of each of the two outer circumferential stripes maybe 2 to 30 mm, more particularly 10 mm to 30 mm, 5 mm to 25 mm, 15 mm to25 mm, or 15 mm to 20 mm. In the embodiments that include threecircumferential stripes, the uniform width of the center circumferentialstripe may be 0.5 mm to 15 mm, more particularly 1 mm to 12 mm, 1 mm to10 mm, or 1 mm to 8 mm. In the embodiments that include threecircumferential stripes, the uniform total width of the three stripescombined may be 1 mm to 40 mm, more particularly 5 mm to 35 mm, 10 mm to30 mm, or 15 mm to 25 mm.

In one embodiment, two circular or semi-spherical pole stamps can beapplied to the golf ball so that the stripe is created by the gapbetween those two pole stamps. In such case, the stripe is not paintedonto a base paint layer but rather is formed by revealing the base paintlayer between the two pole stamps. Any of the embodiments describedherein can be achieved by painting two large pole stamps to revealcomplex stripe geometries of the base paint layer or lower paint layerbeneath the pole stamps.

The circumferential stripe(s) may be created on the golf ball by anytype of printing or application method. An illustrative method is inkpad printing. Another method is ink jet printing. In certainembodiments, the first surface area portion and the second surface areaportion are initially formed via casting of the cover layer.Subsequently, the circumferential stripe(s) are applied to the surfaceof the cover layer.

Examples of embodiments of a golf ball with only three colors is shownin FIGS. 2A-2C. The cover layer of the golf ball includes a firstsurface area portion 10 of a first color and a second surface areaportion 11 of a second color. The first surface area portion 10 and thesecond surface area portion 11 are formed by casting a first castablepolyurethane or polyurea composition that includes a first coloradditive and a second castable polyurethane or polyurea composition thatincludes a second color additive, wherein the first color and the secondcolor are different or contrasting colors. In certain embodiments a seamis located where two halves of a mold come together during manufacturingof the golf ball.

The surface of the golf balls in FIGS. 2A-2C also includes acircumferential stripe 12 of a third color that is located between thefirst surface area portion 10 and the second surface area portion 11. Incertain embodiments the circumferential stripe 12 is located at or nearthe seam. In certain embodiments, the circumferential stripe 12 forms adividing line between the first surface area portion 10 and the secondsurface area portion 11 wherein a first boundary 13 of the stripe 12contacts the first surface area portion 10 and a second boundary 14 ofthe stripe contact the second surface area portion 11. In certainembodiments, the first surface area portion 10 and the second surfacearea portion 11 each individually cover 10 to 49%, more particularly 20to 45%, 25 to 40%, or 30 to 40% of the total ball surface area. Incertain embodiments, the surface area of the first surface area portion10 is equal to the surface area of the second surface area portion 11.The first surface area portion and the second surface area portion eachmay be dome-shaped or frusto-spherical-shaped. “Frusto-spherical” asused herein describes a portion of a full sphere that is terminated atone end by a transverse plane. The respective colors are uniformlypresent over the entire surface area of each of 10 and 11. In certainembodiments, a stripe 12 portion of the ball can cover 1 to 50%, 2 to40%, or 3 to 25% of the total surface area of the golf ball.

Additional embodiments of multi-color golf balls are shown in FIGS.3A-3C. The cover layer of the golf ball includes a first surface areaportion 20 of a first color and a second surface area portion 21 of asecond color. The first surface area portion 20 and the second surfacearea portion 21 are formed by casting a first castable polyurethane orpolyurea composition that includes a first color additive and a secondcastable polyurethane or polyurea composition that includes a secondcolor additive, wherein the first color and the second color aredifferent or contrasting colors. In certain embodiments a seam islocated where two halves of a mold come together during manufacturing ofthe golf ball.

The surface of the golf balls in FIGS. 2A-2C also includes a centercircumferential stripe 22, a first outer circumferential stripe 23, anda second outer circumferential stripe 24. All three stripes 22, 23 and24 are located between the first surface area portion 20 and the secondsurface area portion 21. The center stripe 22 is located between therespective outer stripes 23 and 24. In certain embodiments the centerstripe 22 is located at or near the seam. The center stripe 22 isdefined by a first boundary 25 and an opposing second boundary 26. Thefirst outer stripe 23 is defined by a first boundary 27 and an opposingsecond boundary 28. The second outer stripe 24 is defined by a firstboundary 29 and an opposing second boundary 30. The first boundary 25 ofthe center stripe 22 contacts the second boundary 28 of the first outerstripe 23. The second boundary 26 of the center stripe 22 contacts thesecond boundary 30 of the second outer stripe 24. The first boundary 27of the first outer stripe 23 contacts the first surface area portion 20.The first boundary 29 of the second outer stripe 24 contacts the secondsurface area portion 21.

In certain embodiments, the first surface area portion 20 and the secondsurface area portion 21 each individually cover 10 to 49%, moreparticularly 20 to 45%, 25 to 40%, or 30 to 40% of the total ballsurface area. In certain embodiments, the surface area of the firstsurface area portion 20 is equal to the surface area of the secondsurface area portion 21. In one embodiment, the first surface areaportion 20 and second surface area portion 21 are substantially similarin covering a substantially similar surface area percentage of the ballwithin 5% of each other. In other words, the first surface area portion20 covers a certain percentage of the total ball surface area that iswithin 5% of the second surface area portion 21. The first surface areaportion 20 and the second surface area portion 21 each may bedome-shaped or frusto-spherical-shaped. The respective colors areuniformly present over the entire surface area of each of 20 and 21.

In certain embodiments, both of the outer stripes 23, 24 are the samecolor, preferably white. In certain embodiments, the center stripe 22and each of the first surface area portion 20 and the second surfacearea portion 21 are all the same color. In certain embodiments, both thefirst surface area portion 20 and the second surface area portion 21 area first color, the center stripe 22 is a second color, and both theouter stripes 23, 24 are a third color, wherein the first color, thesecond color, and the third color are different or contrasting colors.

FIG. 3D is an illustrative example of a multi-color golf ball 40 alignedwith a putter head 41. The putter head 41 includes a center alignmentmark 42 located between a first alignment border 43 and a secondalignment border 44. The center alignment mark 42 is aligned with thecenter circumferential stripe 22, the first alignment border 43 isaligned with the first outer circumferential stripe 23, and the secondalignment border 44 is aligned with the second outer circumferentialstripe 24. In certain embodiments, the color of the center alignmentmark 43 is the same as the color of the center circumferential stripe22, the color of the first alignment border 43 is the as the color ofthe first outer circumferential stripe 23, and the color of the secondalignment border 44 is the same as the color of the second outercircumferential stripe 24.

The boundary of the first surface area portion, the second surface areaportion, and the at least one circumferential stripe is defined by achange in color. For example, a change in color value, hue and/or chromacan create a boundary.

The term “contrast” or “contrasting” as used herein refers to two colorsthat are visually distinct from one another. The visibly distinct colorscan be part of the visible light spectrum or can be white or black orany other color. In some embodiments, a color residing in a differentwavelength can be considered “contrasting”. For example, the first,second, or third colors (or however many colors are used on the ballsurface) are each within a color wavelength category. For example, onecontrasting color may be in the violet category having a wavelength of380 to 450 nm, a frequency of 680 to 790 THz, and a photon energy of2.95 to 3.10 eV. In another example, one of the contrasting colors maybe in the blue category having a wavelength of 450 to 485 nm, afrequency of 620 to 680 THz, and a photon energy of 2.64 to 2.75 eV. Inanother example, one of the contrasting colors may be in the cyancategory having a wavelength of 485 to 500 nm, a frequency of 600 to 620THz, and a photon energy of 2.48 to 2.52 eV. In another example, one ofthe contrasting colors may be in the green category having a wavelengthof 500 to 565 nm, a frequency of 530 to 600 THz, and a photon energy of2.25 to 2.34 eV. In another example, one of the contrasting colors maybe in the yellow category having a wavelength of 565 to 590 nm, afrequency of 510 to 530 THz, and a photon energy of 2.10 to 2.17 eV. Inanother example, one of the contrasting colors may be in the orangecategory having a wavelength of 590 to 625 nm, a frequency of 480 to 510THz, and a photon energy of 2.00 to 2.10 eV. In another example, one ofthe contrasting colors may be in the red category having a wavelength of625 to 740 nm, a frequency of 405 to 480 THz, and a photon energy of1.65 to 2.00 eV.

Examples are also described, for convenience, with respect to CIELabcolor spaced using L*a*b* color values or L*C*h color values, but othercolor descriptions can be used. As used herein, L* is referred to aslightness, a* and b* are referred to as chromaticity coordinates, C* isreferred to as chroma, and h is referred to as hue. In the CIELab colorspace, +a* is a red direction, −a* is a green direction, +b* is a yellowdirection, and −b* is the blue direction. L* has a value of 100 for aperfect white diffuser. Chroma and hue are polar coordinates associatedwith a* and b*, wherein chroma (C*) is a distance from the axis alongwhich a*=b*=0 and hue is an angle measured counterclockwise from the +a*axis. The following description is generally based on values associatedwith standard illuminant D65 at 10 degrees. This illuminant is similarto outside daylight lighting, but other illuminants can be used as well,if desired, and tabulated data provided herein generally includes valuesfor illuminant A at 10 degrees and illuminant F2 at 10 degrees. Theseilluminants are noted in tabulated data simply as D, A, and F forconvenience. The terms brightness and intensity are used in thefollowing description to refer to CIELab coordinate L*.

For convenient description, standard golf illumination is defined hereinas illumination associated with common outdoor playing conditions innatural lighting, i.e., full sun, partial sun, partial shade, fullshade, and overcast conditions at times a few hours after sunrise and afew hours before sunset.

In certain embodiments, a golf ball surface may have at least a firstcolor or a second color having a CIELab lightness (L) of 0 to 100, moreparticularly 0 to 30, 30 to 60, or 60 to 90, a CIELab “a” value of −100to 100, more particularly −90 to −20, −20 to 20, or 20 to 90, and aCIELab b value of −100 to 100, more particularly 40 to 90, −40 to 40, or−40 to −90. The first or second color may be a white blue, green yellow,orange, pink, red, purple, blue, or turquoise

In certain embodiments, a golf ball surface may have at least a firstcontrasting color and a second contrasting color wherein the absolutevalue difference between CIELab L values for the first contrasting colorand the second contrasting color is at between 1 and 15, between 3 and12, between 4 and 11, between 5 and 10, between 30 and 90, between 40and 80, between 50 and 70, between 55 and 65, 25 and 75, between 30 and70, between 40 and 60, or between 45 and 55. In certain embodiments, agolf ball surface may have at least a first contrasting color and asecond contrasting color wherein the absolute value difference betweenCIELab “a” values for the first contrasting color and the secondcontrasting color is at between 0.1 and 10, between 0.2 and 7, between0.3 and 5, between 3 and 20, between 5 and 18, between 10 and 15,between 20 and 60, between 30 and 50, or between 35 and 45. In certainembodiments, a golf ball surface may have at least a first contrastingcolor and a second contrasting color wherein the absolute valuedifference between CIELab b values for the first contrasting color andthe second contrasting color is between 3 and 12, between 4 and 11,between 5 and 10 between 50 and 100, between 60 and 95, between 70 and95, between 5 and 50, between 10 and 40, or between 15 and 30.

In one embodiment, predominant white color of the golf ball has a CIELablightness (L) of between 80 to 100, more particularly between 85 to 99,or between 90 to 99, a CIELab “a” value of between −5 to 0, moreparticularly between −4 to 0, and a CIELab b value of between −10 to 0,more particularly between −9 to 0, or between −8 to −2. The base coloror predominant color may be white, black, red, yellow, blue, green,orange, purple, or any primary, secondary, or tertiary color orcombination of any of the above.

In certain embodiments, the first color or second color may have aCIELab lightness (L) of 15 to 35, more particularly 20 to 30 or 25 to30, a CIELab “a” value of −2.9 to 3, more particularly −2.5 to 1, and aCIELab b value of −1 to 10, more particularly 0 to 5 or 0 to 3. Inanother embodiment, the first or a second color may have a CIELablightness (L) of 60 to 100, more particularly 70 to 90, or 75 to 85, aCIELab “a” value of 5 to 15, more particularly 8 to 12, or 9 to 11, anda CIELab b value of 60 to 100, more particularly 70 to 90, or 75 to 85.In yet another embodiment, the first or second color may have a CIELablightness (L) of 30 to 50, more particularly 36 to 45, or 38 to 42, aCIELab “a” value of 30 to 50, more particularly 35 to 45, or 38 to 42,and a CIELab b value of 10 to 20, more particularly 12 to 18 or 13 to15.

In certain embodiments, the first and second color may be a firstcontrasting color and a second contrasting color wherein the absolutevalue difference between CIELab L values for the first contrasting colorand the second contrasting color is at between 5 to 70, between 10 to60, or more particularly between 10 to 55. In certain embodiments, thefirst contrasting color and a second contrasting color can have anabsolute value difference between CIELab “a” values for the firstnon-white or contrasting color and the second non-white or contrastingcolor is at between 3 and 50, between 5 and 45, or more particularlybetween 6 and 42. In certain embodiments, the first color and secondcolor may be a first contrasting color and a second contrasting colorwherein the absolute value difference between CIELab b values for thefirst contrasting color and the second contrasting color is between 5and 90, between 10 and 85, or more particularly between 10 and 80.

In one embodiment, the ΔE*ab values are measured from the first colorwhich can be a dominant white color of the golf ball or a base colorthat can be white or non-white. In another embodiment, the ΔE*ab iscalculated for the the second color utilizing the first color as thetarget color or specimen.

The value of ΔE*ab is calculated according the below equation in Eq. 1:

ΔE*ab=√(ΔL)2+(Δa)2+(Δb)2  Eq.1

Where

ΔL is the lightness difference between the first color and the specimenhaving the second color being evaluated; andΔa, Δb are differences of the CIE 1976 a*and b*co-ordinates,respectively.

The ΔE*ab values for the second color can be either Black 3C or Black Crelative to the first color of the golf ball. In one embodiment, theΔE*ab of the second color relative to the first color is between 40 and80, between 50 and 70, or between 55 and 65.

In one embodiment, the ΔE*ab value of the second color is between 70 and110, between 80 and 100 or between 85 and 95 relative to the firstcolor. In yet another embodiment, the ΔE*ab value of the second color isbetween 80 and 110, between 85 and 105, or between 90 and 100 when thetarget color is the first color.

In one embodiment, the ΔE*ab value of the second color is between 50 and90, between 60 and 80 or between 65 and 75 relative to the first color.In yet another embodiment, the ΔE*ab value of a third color is between25 and 55, between 30 and 50, or between 35 and 45 when the target coloris the first color. In yet another embodiment, the ΔE*ab value of thethird color is between 65 and 95, between 70 and 90, or between 75 and85 when the target color is the second color.

In one embodiment where the ball has a base first color and at least twostripes containing a second color and a third color, the ΔE*ab values ofthe second and third color relative to the first color of the ball arebetween 40 and 100, between 50 and 95, or between 60 and 95. In oneembodiment, the ΔE*ab values of the second and third color relative tothe first color of the ball are between 30 and 110, between 35 and 98,or between 40 and 97. In some embodiments, where the golf ball has twocolors or more, such as two to ten colors, or three to ten colors, theΔE*ab values of all the image colors relative to the base color of theball are between 40 and 100, between 50 and 95, or between 60 and 95.

The multi-color cover layer facilitates visibility of the ball. Forexample, a first color may enhance ball visibility in low visibilityplaying light, a second color may enhance ball visibility in mediumvisibility playing light, a third color may enhance ball visibility inhigh visibility playing light.

In the embodiments shown in FIG. 1, the boundary between first surfacearea portion, and the second surface area portion provide enhancedputting feedback by providing the golfer with a contrasting line ofcolor to align with alignment aides located on the golf club. Similarly,in the embodiments shown in FIGS. 2A-2C and 3A-3D, the circumferentialstripe(s) provide enhanced putting feedback by allowing the golfer toalign such stripes with similar or identical markings located on thegolf club.

The circumferential stripe(s) also functions as a contrasting alignmentfeature allowing the golfer to more easily align the ball prior toimpact with a golf club. For example, in the embodiment shown in FIG. 3Dthe center circumferential stripe can be aligned with an alignment markprovided on a putter head. In some embodiments, the alignment color andline width and spacing between the lines on the golf ball is identicalto the alignment color, line width and spacing between the lines on theputter head.

Castable Polyurethane or Polyurea Compositions, and Methods of Making,for the Multi-Color Cover Layer

In certain embodiments, the cast polyurethane or polyurea covercomposition is a thermoset polyurethane or polyurea or a thermoplasticpolyurethane or polyurea. In certain embodiments, the cast polyurethaneor polyurea is the only polymer present in the cover layer.

Polyurethanes or polyureas typically are prepared by reacting adiisocyanate with a polyol (in the case of polyurethanes) or with apolyamine (in the case of a polyurea). Thermoplastic polyurethanes orpolyureas may consist solely of this initial mixture or may be furthercombined with a chain extender to vary properties such as hardness ofthe thermoplastic. Thermoset polyurethanes or polyureas typically areformed by the reaction of a diisocyanate and a polyol or polyaminerespectively, and an additional crosslinking agent to crosslink or curethe material to result in a thermoset.

A two-step process may occur in which the first step involves reactingthe diisocyanate and the polyol (in the case of polyurethane) or thepolyamine (in the case of a polyurea) to form a so-called prepolymer, towhich can then be added either the chain extender or the curing agent.This procedure is known as the prepolymer process.

In addition, although depicted as discrete component packages as above,it is also possible to control the degree of crosslinking, and hence thedegree of thermoplastic or thermoset properties in a final composition,by varying the stoichiometry not only of the diisocyanate-to-chainextender or curing agent ratio, but also the initialdiisocyanate-to-polyol or polyamine ratio. Of course in the prepolymerprocess, the initial diisocyanate-to-polyol or polyamine ratio is fixedon selection of the required prepolymer.

In certain embodiments, the cast thermoset polyurethane covercomposition is made by reacting together at least one polyurethaneprepolymer, at least one diol or polyol, at least one diamine chainextender, at least one curing catalyst, and at least one color additive.Optional ingredients for inclusion in the composition include at leastone UV inhibitor.

The amount of polyurethane prepolymer included in the castable covercomposition may range from 50 to 95%, more particularly 70% to 92%.

The amount of diol or polyol included in the castable cover compositionmay range between 0% to 30%, more particularly between 0% to 10%.

The amount of diamine included in the castable cover composition mayrange from 5% to 30%, more particularly 6% to 20%.

The amount of UV inhibitor included in the castable cover compositionmay range from between 0% to 5%, more particularly between 0.5% to 3%.

The amount of curing catalyst included in the castable cover compositionmay range from between 0% to 5%, more particularly between 0.5% to 3%.

In certain embodiments, the color additive(s) may be included in aliquid color concentrate that includes at least one ingredient inaddition to the color additive. The additional ingredient may be, forexample, a plasticizer and/or polyol, pigment(s), surfactants, solvents,functional additives, thickeners, and UV stabilizers. The colorconcentrate may be added to any of the ingredient(s) of the castablecomposition prior to, or during, casting. The amount of colorconcentrate in the cover composition may range from between 0 to 5%,more particularly between 1% to 4%, or more particularly between 2% to3%.

Illustrative polyurethane prepolymers include those made by reacting anisocyanate and a diol or polyol.

Isocyanates include, but are not limited to, aliphatic, cycloaliphatic,aromatic aliphatic, aromatic, any derivatives thereof, and combinationsof these compounds having two or more isocyanate (NCO) groups permolecule. As used herein, aromatic aliphatic compounds should beunderstood as those containing an aromatic ring, wherein the isocyanategroup is not directly bonded to the ring. One example of an aromaticaliphatic compound is a tetramethylene diisocyanate (TMXDI). Theisocyanates may be organic polyisocyanate-terminated prepolymers, lowfree isocyanate prepolymer, and mixtures thereof. Theisocyanate-containing reactable component also may include anyisocyanate-functional monomer, dimer, trimer, or polymeric adductthereof, prepolymer, quasi-prepolymer, or mixtures thereof.Isocyanate-functional compounds may include monoisocyanates orpolyisocyanates that include any isocyanate functionality of two ormore.

Suitable isocyanate-containing components include diisocyanates havingthe generic structure: O=C=N—R—N═C═O, where R preferably is a cyclic,aromatic, or linear or branched hydrocarbon moiety containing from about1 to about 50 carbon atoms. The isocyanate also may contain one or morecyclic groups or one or more phenyl groups. When multiple cyclic oraromatic groups are present, linear and/or branched hydrocarbonscontaining from about 1 to about 10 carbon atoms can be present asspacers between the cyclic or aromatic groups. In some cases, the cyclicor aromatic group(s) may be substituted at the 2-, 3-, and/or4-positions, or at the ortho-, meta-, and/or para-positions,respectively. Substituted groups may include, but are not limited to,halogens, primary, secondary, or tertiary hydrocarbon groups, or amixture thereof.

Examples of isocyanates that can be used with the present inventioninclude, but are not limited to, substituted and isomeric mixturesincluding 2,2′-, 2,4′-, and 4,4′-diphenylmethane diisocyanate (MDI);3,3′-dimethyl-4,4′-biphenylene diisocyanate (TODI); toluene diisocyanate(TDI); polymeric MDI; carbodiimide-modified liquid 4,4′-diphenylmethanediisocyanate; para-phenylene diisocyanate (PPDI); meta-phenylenediisocyanate (MPDI); triphenyl methane-4,4′- and triphenylmethane-4,4″-triisocyanate; naphthylene-1,5-diisocyanate; 2,4′-, 4,4′-,and 2,2-biphenyl diisocyanate; polyphenylene polymethylenepolyisocyanate (PMDI) (also known as polymeric PMDI); mixtures of MDIand PMDI; mixtures of PMDI and TDI; ethylene diisocyanate;propylene-1,2-diisocyanate; trimethylene diisocyanate; butylenesdiisocyanate; bitolylene diisocyanate; toluidine diisocyanate;tetramethylene-1,2-diisocyanate; tetramethylene-1,3-diisocyanate;tetramethylene-1,4-diisocyanate; pentamethylenediisocyanate;1,6-hexamethylene diisocyanate (HDI); octamethylenediisocyanate; decamethylene diisocyanate; 2,2,4-trimethylhexamethylenediisocyanate; 2,4,4-trimethylhexamethylene diisocyanate;dodecane-1,12-diisocyanate; dicyclohexylmethane diisocyanate;cyclobutane-1,3-diisocyanate; cyclohexane-1,2-diisocyanate;cyclohexane-1,3-diisocyanate; cyclohexane-1,4-diisocyanate; diethylidenediisocyanate; methylcyclohexylene diisocyanate (HTDI);2,4-methylcyclohexane diisocyanate; 2,6-methylcyclohexane diisocyanate;4,4′-dicyclohexyl diisocyanate; 2,4′-dicyclohexyl diisocyanate;1,3,5-cyclohexane triisocyanate; isocyanatomethylcyclohexane isocyanate;1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane;isocyanatoethylcyclohexane isocyanate; bis(isocyanatomethyl)-cyclohexanediisocyanate; 4,4′-bis(isocyanatomethyl) dicyclohexane;2,4′-bis(isocyanatomethyl) dicyclohexane; isophorone diisocyanate(IPDI); dimeryl diisocyanate, dodecane-1,12-diisocyanate,1,10-decamethylene diisocyanate, cyclohexylene-1,2-diisocyanate,1,10-decamethylene diisocyanate, 1-chlorobenzene-2,4-diisocyanate,furfurylidene diisocyanate, 2,4,4-trimethyl hexamethylene diisocyanate,2,2,4-trimethyl hexamethylene diisocyanate, dodecamethylenediisocyanate, 1,3-cyclopentane diisocyanate, 1,3-cyclohexanediisocyanate, 1,3-cyclobutane diisocyanate, 1,4-cyclohexanediisocyanate, 4,4′-methylenebis(cyclohexyl isocyanate),4,4′-methylenebis(phenyl isocyanate), 1-methyl-2,4-cyclohexanediisocyanate, 1-methyl-2,6-cyclohexane diisocyanate, 1,3-bis(isocyanato-methyl)cyclohexane,1,6-diisocyanato-2,2,4,4-tetra-methylhexane,1,6-diisocyanato-2,4,4-tetra-trimethylhexane,trans-cyclohexane-1,4-diisocyanate,3-isocyanato-methyl-3,5,5-trimethylcyclo-hexyl isocyanate,1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane, cyclohexylisocyanate, dicyclohexylmethane 4,4′-diisocyanate,1,4-bis(isocyanatomethyl) cyclohexane, m-phenylene diisocyanate,m-xylylene diisocyanate, m-tetramethylxylylene diisocyanate, p-phenylenediisocyanate, p,p′-biphenyl diisocyanate, 3,3′-dimethyl-4,4′-biphenylenediisocyanate, 3,3′-dimethoxy-4,4′-biphenylene diisocyanate,3,3′-diphenyl-4,4′-biphenylene diisocyanate, 4,4′-biphenylenediisocyanate, 3,3′-dichloro-4,4′-biphenylene diisocyanate,1,5-naphthalene diisocyanate, 4-chloro-1,3-phenylene diisocyanate,1,5-tetrahydronaphthalene diisocyanate, metaxylene diisocyanate,2,4-toluene diisocyanate, 2,4′-diphenylmethane diisocyanate,2,4-chlorophenylene diisocyanate, 4,4′-diphenylmethane diisocyanate,p,p′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate,2,6-tolylene diisocyanate, 2,2-diphenylpropane-4,4′-diisocyanate,4,4′-toluidine diisocyanate, dianidine diisocyanate, 4,4′-diphenyl etherdiisocyanate, 1, 3-xylylene diisocyanate, 1,4-naphthylene diisocyanate,azobenzene-4,4′-diisocyanate, diphenyl sulfone-4,4′-diisocyanate,triphenylmethane 4,4′, 4″-triisocyanate, isocyanatoethyl methacrylate,3-isopropenyl-α,α-dimethylbenzyl-isocyanate, dichlorohexamethylenediisocyanate, ω, ω′-diisocyanato-1,4-diethylbenzene, polymethylenepolyphenylene polyisocyanate, isocyanurate modified compounds, andcarbodiimide modified compounds, as well as biuret modified compounds ofthe above polyisocyanates. These isocyanates may be used either alone orin combination. These combination isocyanates include triisocyanates,such as biuret of hexamethylene diisocyanate and triphenylmethanetriisocyanates, and polyisocyanates, such as polymeric diphenylmethanediisocyanate.triisocyanate of HDI; triisocyanate of2,2,4-trimethyl-1,6-hexane diisocyanate (TMDI); 4,4′-dicyclohexylmethanediisocyanate (Hi2MDI); 2,4-hexahydrotoluene diisocyanate;2,6-hexahydrotoluene diisocyanate; 1,2-, 1,3-, and 1,4-phenylenediisocyanate; aromatic aliphatic isocyanate, such as 1,2-, 1,3-, and1,4-xylene diisocyanate; meta-tetramethylxylene diisocyanate (m-TMXDI);para-tetramethylxylene diisocyanate (p-TMXDI); trimerized isocyanurateof any polyisocyanate, such as isocyanurate of toluene diisocyanate,trimer of diphenylmethane diisocyanate, trimer of tetramethylxylenediisocyanate, isocyanurate of hexamethylene diisocyanate, and mixturesthereof, dimerized uretdione of any polyisocyanate, such as uretdione oftoluene diisocyanate, uretdione of hexamethylene diisocyanate, andmixtures thereof; modified polyisocyanate derived from the aboveisocyanates and polyisocyanates; and mixtures thereof.

In certain embodiments, the isocyanate is toluene diisocyanate.

Polyols used for making the polyurethane in the copolymer includepolyester polyols, polyether polyols, polycarbonate polyols andpolybutadiene polyols. Polyester polyols are prepared by condensation orstep-growth polymerization utilizing diacids. Primary diacids forpolyester polyols are adipic acid and isomeric phthalic acids. Adipicacid is used for materials requiring added flexibility, whereas phthalicanhydride is used for those requiring rigidity. Some examples ofpolyester polyols include poly(ethylene adipate) (PEA), poly(diethyleneadipate) (PDA), poly(propylene adipate) (PPA), poly(tetramethyleneadipate) (PBA), poly(hexamethylene adipate) (PHA), poly(neopentyleneadipate) (PNA), polyols composed of 3-methyl-1,5-pentanediol and adipicacid, random copolymer of PEA and PDA, random copolymer of PEA and PPA,random copolymer of PEA and PBA, random copolymer of PHA and PNA,caprolactone polyol obtained by the ring-opening polymerization ofε-caprolactone, and polyol obtained by opening the ring ofβ-methyl-δ-valerolactone with ethylene glycol can be used either aloneor in a combination thereof. Additionally, polyester polyol may becomposed of a copolymer of at least one of the following acids and atleast one of the following glycols. The acids include terephthalic acid,isophthalic acid, phthalic anhydride, oxalic acid, malonic acid,succinic acid, pentanedioic acid, hexanedioic acid, octanedioic acid,nonanedioic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioicacid, dimer acid (a mixture), p-hydroxybenzoate, trimellitic anhydride,ε-caprolactone, and β-methyl-δ-valerolactone. The glycols includeethylene glycol, propylene glycol, butylene glycol, pentylene glycol,1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentylene glycol,polyethylene glycol, polytetramethylene glycol, 1,4-cyclohexanedimethanol, pentaerythritol, and 3-methyl-1,5-pentanediol.

Polyether polyols are prepared by the ring-opening additionpolymerization of an alkylene oxide (e.g. ethylene oxide and propyleneoxide) with an initiator of a polyhydric alcohol (e.g. diethyleneglycol), which is an active hydride. Specifically, polypropylene glycol(PPG), polyethylene glycol (PEG) or propylene oxide-ethylene oxidecopolymer can be obtained. Polytetramethylene ether glycol (PTMG) isprepared by the ring-opening polymerization of tetrahydrofuran, producedby dehydration of 1,4-butanediol or hydrogenation of furan.Tetrahydrofuran can form a copolymer with alkylene oxide. Specifically,tetrahydrofuran-propylene oxide copolymer or tetrahydrofuran-ethyleneoxide copolymer can be formed. A polyether polyol may be used eitheralone or in a mixture.

Polycarbonate polyol is obtained by the condensation of a known polyol(polyhydric alcohol) with phosgene, chloroformic acid ester, dialkylcarbonate or diallyl carbonate. A particularly preferred polycarbonatepolyol contains a polyol component using 1,6-hexanediol, 1,4-butanediol,1,3-butanediol, neopentylglycol or 1,5-pentanediol. A polycarbonatepolyol can be used either alone or in a mixture.

Polybutadiene polyol includes liquid diene polymer containing hydroxylgroups, and an average of at least 1.7 functional groups, and may becomposed of diene polymer or diene copolymer having 4 to 12 carbonatoms, or a copolymer of such diene with addition to polymerizableα-olefin monomer having 2 to 2.2 carbon atoms. Specific examples includebutadiene homopolymer, isoprene homopolymer, butadiene-styrenecopolymer, butadiene-isoprene copolymer, butadiene-acrylonitrilecopolymer, butadiene-2-ethyl hexyl acrylate copolymer, andbutadiene-n-octadecyl acrylate copolymer. These liquid diene polymerscan be obtained, for example, by heating a conjugated diene monomer inthe presence of hydrogen peroxide in a liquid reactant. A polybutadienepolyol can be used either alone or in a mixture.

Diisocyanate and polyol or polyamine components may be combined to forma prepolymer prior to reaction with a chain extender or curing agent.Any such prepolymer combination is suitable for use in the presentinvention. Commercially available prepolymers include LFH580, LFH120,LFH710, LFH1570, LF930A, LF950A, LF601D, LF751D, LFG963A, LFG640D.

One preferred prepolymer is a toluene diisocyanate prepolymer withpolypropylene glycol. Such polypropylene glycol terminated toluenediisocyanate prepolymers are available from Uniroyal Chemical Company ofMiddlebury, Conn., under the trade name ADIPRENE® LFG963A and LFG640D.Most preferred prepolymers are the polytetramethylene ether glycolterminated toluene diisocyanate prepolymers including those availablefrom Uniroyal Chemical Company of Middlebury, Conn., under the tradename ADIPRENE® LF930A, LF950A, LF601D, and LF751D.

In one embodiment, the number of free NCO groups in the urethane or ureaprepolymer may be less than about 14 percent. Preferably the urethane orurea prepolymer has from about 3 percent to about 11 percent, morepreferably from about 4 to about 9.5 percent, and even more preferablyfrom about 3 percent to about 9 percent, free NCO on an equivalentweight basis.

The polyurethane also may incorporate chain extenders. Non-limitingexamples of these extenders include polyols, polyamine compounds, andmixtures of these. Polyol extenders may be primary, secondary, ortertiary polyols. Specific examples of monomers of these polyolsinclude: trimethylolpropane (TMP), ethylene glycol, 1,3-propanediol,1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, propylene glycol,dipropylene glycol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol,1,2-pentanediol, 2,3-pentanediol, 2,5-hexanediol, 2,4-hexanediol,2-ethyl-1,3-hexanediol, cyclohexanediol, and2-ethyl-2-(hydroxymethyl)-1,3-propanediol.

Suitable polyamines that may be used as chain extenders include primary,secondary and tertiary amines; polyamines have two or more amines asfunctional groups. Examples of these include: aliphatic diamines, suchas tetramethylenediamine, pentamethylenediamine, hexamethylenediamine;alicyclic diamines, such as 3,3′-dimethyl-4,4′-diamino-dicyclohexylmethane; or aromatic diamines, such as 4,4′-methylenebis-2-chloroaniline, 2,2′, 3,3′-tetrachloro-4,4′-diaminophenyl methane,p,p′-methylenedianiline, p-phenylenediamine or 4,4′-diaminodiphenyl; and2,4,6-tris(dimethylaminomethyl) phenol. Aromatic diamines have atendency to provide a stiffer product than aliphatic or cycloaliphaticdiamines. A chain extender may be used either alone or in a mixture.

In certain embodiments, a diamine chain extender and a diol chainextender are both included in the composition.

In certain embodiments, the diamine is 3,5-diethyltoluene-2,4-diamine,3,5-diethyltoluene-2,6-diamine, or a mixture thereof. In certainembodiments, the diol is 1,4-butanediol.

The color additive may be a pigment or a dye. Illustrative coloradditives include materials that include at least one metal-containingingredient. In certain embodiments the metal-containing ingredient is orincludes a transition metal element, a post transition metal element, ametalloid element, or a mixture thereof. Illustrative transitionelements include Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo,Tc, Ru, Rh, Pd, Ag, Cd, La, Hf, Ta, W, Re, Os, Ir, Pt, Au and Hg.Illustrative post transition elements include Al, Ga, Ge, In, Sn, Sb,Tl, Pb, Bi, and Po. Illustrative metalloid elements include B, Si, Ge,As, Sb, Te, and to a lesser extent C, Se, Po, At. In certainembodiments, the metal-containing ingredient is a transition metaloxide, transition metal halide, transition metal hydrate or transitionmetal phosphate. In certain embodiments, the post transition metalcompound is a post transition metal oxide, post transition metal halide,post transition metal hydrate or post transition metal phosphate.Particularly preferred metal-containing ingredients include titaniumdioxide, manganese oxide (Mn₂O₃), iron (III) oxide, zinc oxide, aluminumoxide (Al₂O₃), bismuth aluminate hydrate and aluminum phosphate.

In certain embodiments the metal-containing ingredient is mixed metaloxide. The mixed metal oxide may be a mixed metal oxide pigment. Mixedmetal oxide pigments are compounds comprised of a group of two or moremetals and oxygen. The most common crystal structures are rutile (MeO₂)hematite (Me₂O₃) or spinel (Me₃O₄). Metals commonly present include:cobalt, iron, trivalent chrome, tin, antimony, titanium, manganese andaluminum.

Depending on their chemical structure, curing agents may be slow- orfast-reacting polyamines or polyols. As described in U.S. Pat. Nos.6,793,864, 6,719,646 and copending U.S. Patent Publication No.2004/0201133 A1, (the contents of all of which are hereby incorporatedherein by reference), slow-reacting polyamines are diamines having aminegroups that are sterically and/or electronically hindered by electronwithdrawing groups or bulky groups situated proximate to the aminereaction sites. The spacing of the amine reaction sites will also affectthe reactivity speed of the polyamines.

Suitable curatives for use in the present invention are selected fromthe slow-reacting polyamine group include, but are not limited to,3,5-dimethylthio-2,4-toluenediamine;3,5-dimethylthio-2,6-toluenediamine; N,N′-dialkyldiamino diphenylmethane; trimethylene-glycol-di-p-aminobenzoate;polytetramethyleneoxide-di-p-aminobenzoate, and mixtures thereof. Ofthese, 3,5-dimethylthio-2,4-toluenediamine and3,5-dimethylthio-2,6-toluenediamine are isomers and are sold under thetrade name ETHACURE® 300 by Ethyl Corporation. Trimethyleneglycol-di-p-aminobenzoate is sold under the trade name POLACURE 740M andpolytetramethyleneoxide-di-p-aminobenzoates are sold under the tradename POLAMINES by Polaroid Corporation. N,N′-dialkyldiamino diphenylmethane is sold under the trade name UNILINK® by UOP.

When slow-reacting polyamines are used as the chain extender, a catalystis typically needed to promote the reaction between the urethaneprepolymer and the chain extender. Specific suitable catalysts includeTEDA (1) dissolved in di-propylene glycol (such as TEDA L33 availablefrom Witco Corp. Greenwich, Conn., and DABCO 33 LV available from AirProducts and Chemicals Inc.). Catalysts are added at suitable effectiveamounts, such as from about 2% to about 5%, and (2) more preferably TEDAdissolved in 1,4-butane diol from about 2% to about 5%. Another suitablecatalyst includes a blend of 0.5% 33LV or TEDA L33 (above) with 0.1%dibutyl tin dilaurate (available from Witco Corp. or Air Products andChemicals, Inc.) which is added to a curative such as VIBRACURE® A250.Unfortunately, as is well known in the art, the use of a catalyst canhave a significant effect on the ability to control the reaction andthus, on the overall processability.

To eliminate the need for a catalyst, a fast-reacting curing agent, oragents, can be used that does not have electron withdrawing groups orbulky groups that interfere with the reaction groups. However, theproblem with lack of control associated with the use of catalysts is notcompletely eliminated since fast-reacting curing agents also arerelatively difficult to control.

Preferred curing agent blends include using dicyandiamide in combinationwith fast curing agents such as diethyl-2,4-toluenediamine,4,4″-methylenebis-(3-chloro,2,6-diethyl)-aniline (available from AirProducts and Chemicals Inc., of Allentown, Pa., under the trade nameLONZACURE®), 3,3′-dichlorobenzidene; 3,3′-dichloro-4,4′-diaminodiphenylmethane (MOCA); N,N,N′,N′-tetrakis(2-hydroxypropyl) ethylenediamine andCuralon L, a trade name for a mixture of aromatic diamines sold byUniroyal, Inc. or any and all combinations thereof. A preferredfast-reacting curing agent is diethyl-2,4-toluene diamine, which has twocommercial grades names, Ethacure® 100 and Ethacure® 100LC commercialgrade has lower color and less by-product. In other words, it isconsidered a cleaner product to those skilled in the art.

Advantageously, the use of the Ethacure® 100LC commercial grade resultsin a golf ball that is less susceptible to yellowing when exposed to UVlight conditions. A player appreciates this desirable aesthetic effectalthough it should be noted that the instant invention may use either ofthese two commercial grades for the curing agentdiethyl-2,4-toluenediamine.

If a reduced-yellowing post curable composition is required, the chainextender or curing agent can further comprise a peroxide or peroxidemixture. Before the composition is exposed to sufficient thermal energyto reach the activation temperature of the peroxide, the composition of(a) and (b) behaves as a thermoplastic material. Therefore, it canreadily be formed into golf ball layers using injection molding.However, when sufficient thermal energy is applied to bring thecomposition above the peroxide activation temperature, crosslinkingoccurs, and the thermoplastic polyurethane is converted into crosslinkedpolyurethane.

Examples of suitable peroxides for use in compositions within the scopeof the present invention include aliphatic peroxides, aromaticperoxides, cyclic peroxides, or mixtures of these. Primary, secondary,or tertiary peroxides can be used, with tertiary peroxides mostpreferred. Also, peroxides containing more than one peroxy group can beused, such as 2,5-bis-(tert-butylperoxy)-2,5-dimethyl hexane and1,4-bis-(tert-butylperoxy-isopropyl)-benzene. Also, peroxides that areeither symmetrical or asymmetric can be used, such astert-butylperbenzoate and tert-butylcumylperoxide. Additionally,peroxides having carboxy groups also can be used. Decomposition ofperoxides used in compositions within the scope of the present inventioncan be brought about by applying thermal energy, shear, reactions withother chemical ingredients, or a combination of these. Homolyticallydecomposed peroxide, heterolytically decomposed peroxide, or a mixtureof those can be used to promote crosslinking reactions in compositionswithin the scope of this invention. Examples of suitable aliphaticperoxides and aromatic peroxides include diacetylperoxide,di-tert-butylperoxide, dibenzoylperoxide, dicumylperoxide,2,5-bis-(t-butylperoxy)-2,5-dimethyl hexane,2,5-dimethyl-2,5-di(benzoylperoxy)hexane,2,5-dimethyl-2,5-di(butylperoxy)-3-hexyne,n-butyl-4,4-bis(t-butylperoxyl) valerate,1,4-bis-(t-butylperoxyisopropyl)-benzene, t-butyl peroxybenzoate,1,1-bis-(t-butylperoxy)-3,3,5 tri-methylcyclohexane, anddi(2,4-dichloro-benzoyl). Peroxides for use within the scope of thisinvention may be acquired from Akzo Nobel Polymer Chemicals of Chicago,Ill., Atofina of Philadelphia, Pa. and Akrochem of Akron, Ohio. Furtherdetails of this post curable system are disclosed in U.S. Pat. No.6,924,337, the entire contents of which are hereby incorporated byreference.

Casting (also called “cast-molding”) is performed in a ball cavityformed by bringing together two mold halves that define respectivehemispherical cavities. Casting is especially suitable for forming thecover of a thermoset material. A precise amount of liquid thermosetresin is introduced into the hemispherical cavities and partially cured(“gelled”). The core is placed in the hemispherical cavity of one moldhalf and supported by the partially cured resin. The second mold half isplaced relative to the first mold half to enclose the core and resin inthe resulting ball cavity. As the mold halves are brought together, theresin flows around the core and forms the cover. The mold body is heatedbriefly to cure the resin, and then cooled for removal of the ball fromthe mold body. Advantages of casting are that it achieves substantialuniformity of cover thickness without having to use centering pins, andit can be performed at a much lower pressure inside the mold thaninjection molding or compression molding. In one embodiment, amulti-colored ball is produced using co-injection molding with a hotrunner process.

In one embodiment having a color contrast between the two halves in thefinished golf ball (see, for example, the embodiment shown in FIG. 1), afirst color-containing composition is dispensed in the hemisphericalcavity of a first mold half, the first color-containing composition ispartially cured, the core is placed in the hemispherical cavity of thefirst mold half and supported by the partially cured resin. A secondcolor-containing composition is dispensed in the hemispherical cavity ofa second mold half, and the mold halves are brought together. The moldbody is heated to cure the both of the color-containing compositions,and then cooled for removal of the ball from the mold body. The ballwill have one half that presents the first color and a second half thatpresents the second color. Dispensing the substantially different colorurethane halves can be achieved with two separate dispensers which wouldeach include a mixing section where the prepolymer and curative cometogether prior to dispensing into the cavity half. Since the sameprepolymer is used in the first and second ball halves and the color istypically added on the curative side a single dispenser option is apossible alternative. An electro-mechanical Y-valve on the curative sideprior to the mixing section would enable two curatives with differentcolors to be used and dispense the first color and the second color atpredetermined sequences.

Printing Processes

In certain embodiments, it is possible that the parting line between thefirst color and the second color won't be precise and linear becausethere may be a small amount of mixing between the two colors at theparting line/seam, or if a seamless dimple design is used. To create alinear intersection between the two colors another high contrast coloror visible marking can be placed on the ball as shown, for example, inFIGS. 2A-2C. This can be accomplished with a paint-and-mask process, butpreferably a printing process is used. To achieve an even linear markingthe ball may be set in a fixture using positioning equipment so themarking would be applied to the parting line. To achieve the appearanceof a continuous line, a series of images can be applied using the padprinting process and rotating the golf ball between the application ofeach stamp. Another option is rotary pad printing where a rotating padand golf ball come together and the image is applied to the golf ballcontinuously. Yet another option is single pass inkjet technology wherethe oriented golf ball passes under or next to a printing head androtates at a predetermined speed to apply a continuous image at theparting line.

With single pass industrial inkjet printers, a golf product passes belowor adjacent to a series of print heads only once, producing highthroughput speeds for mass production. In one embodiment, single passinkjet systems are able to run at extremely high speeds, up to 50 inchesper second and higher.

In order to increase resolution of a printed image in the lateral sense,it is possible to add additional print heads in the print direction andoffset them by a certain number of pixels to double or triple the DPI inthe in track while running at maximum speed. The print width can also beincreased by adding print heads in the cross track to increase the printswath by a factor of the print head width.

In one embodiment, the single pass inkjet printers consist of WW+CYMK.It is also possible to vastly expand the color gamut with the additionof print heads having Orange, Green, and Violet.

In one embodiment, the item being printed upon can be pre-treated with ameans to apply a charge to the surface to improve ink adhesion. Someexamples of pre-treatment methods include corona discharge, flame, orplasma pretreatment.

Golf articles other than golf balls can be printed upon using the singlepass printing processes disclosed herein. Other golf articles include,but are not limited to: metal/wood golf clubs, iron golf clubs, puttergolf clubs, golf club face inserts, golf club sole plates, alignmentaides, custom colors on the golf club head, rangefinders, hats, golfbags, steel shafts, composite shafts, shaft regions located near theclub head, golf grips, golf headcovers, golf face plates or face polymercoatings, golf club topline alignment peels, golf club weights,thermoplastic or thermoset components such as club inserts, metal ringcomponents to a golf club head, golf club badges on irons ormetal/woods, hybrid clubs, composites, metals, plastics, or golf clubwedges. Logos, trademarks, technology names, face scorelines, customimages, club numbers or other indicia located on the club can be printedusing the methods described herein.

FIG. 4 illustrates a single pass printer head 402 and a golf ball 400located in a ball holder 416 having a printed area 404. The ball holder416 is connected to a digital encoder 420 that tracks the preciseorientation of the golf ball 400 during rotation 412. In one example,the ball can be held by a top cup (not shown) in addition to the ballholder 416. The golf ball 400 rotates 412 about a vertical rotation axis406 at a rate of rotation while ink droplets 408 are emitted from theprinter head 402. The throw distance 410 is defined as the distancebetween the closest point 414 on the golf ball 404 and the closest pointon the printer head 402. In other words, with a relatively flat printerhead 402 and a spherical-like ball 400, the throw distance 410 is theminimum distance between the golf ball 400 and the printer head 402. Inone embodiment, the throw distance 410 is between 0 mm to 10 mm, between0.5 mm and 1.5 mm, between 0.1 mm to 7 mm, or between 0.1 and 5 mm.

In one embodiment, the distance the ink droplets travel between the balland the printer head 402 increases at a second reference point 424 thatis located away from the closest point 414. As a result of having afurther distance to travel, the ink dispersion may be less accurate atthe second reference point 424 when compared to the accuracy of the inkimage at the closest point 414. In such circumstances, softwaremodifications may be necessary to the image to accommodate for imagedistortions at locations on the golf ball 400 located near the secondreference point 424. In one embodiment, the second reference point 424is about 12.7 mm away from the closest point 414 as measured along thevertical rotation axis 406.

In another embodiment, a zone of distortion has been identified as aregion of the ball that has significant image distortion due to thedistance of the ball 400 being further from the printer head 402. In oneexample, the upper zone of distortion border 426 and lower zone ofdistortion border 428 begins after an upper boundary distance 430 andlower boundary distance 428, respectively, as measured along thevertical rotation axis 406 away from a center plane 434. The centerplane 434 passes through the closest point 414 and the center of theball 400. The upper zone of distortion 426 begins after the upperboundary distance 430 and continues until the upper most point of theball. The lower zone of distortion 428 begins at the after the lowerboundary distance 432 and continues until the lower most point of theball. In one embodiment, the upper boundary distance 430 and lowerboundary distance 432 is 5 mm away from the center plane 434. Theintended printing image may need to be adjusted in the software programsutilized for printing for image portions located in the upper zone ofdistortion 426 and lower zone of distortion 428. In other embodiments,the lower boundary distance 432 and upper boundary distance 430 may be 6mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm,17 mm, 18 mm, 19 mm, or 20 mm away from the center plane 434. The term“distortion” as used herein shall refer to the ink on an object beingapplied in a manner that the printed image is noticeably different froman intended image design. In simple terms, if an intended image designis superimposed on a printed image, areas of distortion can beidentified.

The ball rotation rate of the golf ball 400 as it rotates 412 about thevertical rotation axis 406 is between 1 to 7 revolutions per second(rps) or between 60 revolutions per minute to 420 revolutions per minute(rpm). In one embodiment, the revolutions per second can be 2 to 3 rpsor as low as between 0.1 rps to 1 rps, or even 0.2 rps to 0.5 rps. Inone embodiment, the ball rotation rate can vary between 1 rpm to 400rpm, between 10 rpm to 300 rpm, between 50 rpm to 320 rpm, 80 rpm to 180rpm, 120 rpm to 180 rpm. The ball rotation rates defined herein arebased on a ball circumference of about 13.4 cm and a ball diameterbetween 1.678 inches to 1.688 inches. In one example, the ball diameteris 1.683 inches with a plus or minus tolerance of 0.005 inches.

In one embodiment, the print rate or scan rate of the printer head 402is between 10 cm/s and 100 cm/s, between 60 cm/s and 90 cm/s, or between75 cm/s and 85 cm/s. The print rate or scan rate is how quickly theprinter head 402 can print an image on a surface without seeingsignificant distortions in the image. In addition, the dispense rate isdefined as the rate of ink being dispensed from the printer head 402. Inone embodiment, the dispense rate or the velocity of the ink droplet isbetween 2 m/s and 10 m/s, between 3 m/s and 9 m/s, between 4 m/s and 8m/s, or between 5 m/s and 7 m/s. In one embodiment, the volume of asingle ink droplet is between 6 to 160 picoliters, between 0 to 200picoliters, between 50 to 150 picoliters between 6 to 42 picoliters,between 12 to 84 picoliters, between 40 to 160 picoliters, or between 75to 125 picoliters.

The resolution of the printed area 404 on the golf ball 400 can varybetween 100 to 1400 dots per inch (dpi), between 200 dpi and 400 dpi,between 300 dpi and 400 dpi, between 320 dpi and 390 dpi, between 1000dpi and 1300 dpi, or between 350 dpi and 370 dpi. The typical firingfrequency of the printer heads can be between 6 to 12 kHz. In oneembodiment, the print swathe width is between 1 mm to 25 mm, 3 mm to 20mm, 4 mm to 15 mm, 5 mm to 10 mm, 25 mm to 200 mm, between 500 to 100mm, or between 60 to 80 mm.

In some embodiment, a plurality of printer heads 402 are utilized foreach color. For example, a black, red, and blue printed area 404 wouldrequire at least three printer heads 402 located in a serial arrangementso as to apply each color in successive stages of printing. The printerheads 402 are capable of printing in at least five colors includingcyan, magenta, yellow, black, and white. It is possible to print in anynumber of colors beyond the CMYK inks depending on how many printerheads 402 are available.

FIG. 5 illustrates a top view of the golf ball 400 as it moves along alinear direction 436 and passes through a first printer head 402A at afirst printer station to apply a first color. After the first color isapplied, the golf ball 400 passes through a first ink curing station418A before proceeding to the second printer head 402B at a secondprinter station to apply a second color. After the second color isapplied to the golf ball 400, the ball 400 is cured at a second inkcuring station 418B. The second ink curing station 418B can be a UVpinning operation where low power level UV light is applied or thesecond ink curing station can be a final curing station where a higherpower level of UV light (when compared to the UV pinning operation) isapplied to cure all the ink applied to the golf ball 400. This processcan be repeated for as many colors as required for printing a certainimage. In one embodiment, there are between 1 and 20 printer heads andbetween 1 and 20 curing stations. In some embodiments, there can be twoor more printer heads per printer station applying at least two or moredifferent colors on the golf ball 400 simultaneously.

As shown in FIG. 9, in one embodiment, the first printer head 402A islocated at a “rotational” printing station, meaning that the object orgolf ball 400 to be printed is rotated along an axis 406 of the golfball 400 relative to the first printer head 402A. The first printer head402A prints at least a first image on the golf ball 400. Additionally, asecond printer head 402B can be connected in the manufacturing processto be located after the rotational printing station. The second printerhead 402B can be located at a “linear” printing station where the secondprinter head 402B is primarily stationary and the golf ball 400 is movedwithout rotation and linearly, or at least in one direction, past thesecond printer head 402B to have at least a second image printed on thegolf ball 400.

In another embodiment, the first printer head 402A may be located at alinear printing station and the second printer head 402B can be locatedat a rotational printing station.

In yet another embodiment, the first printer head 402A and the secondprinter head 402B can both be rotational printing stations.

In yet another embodiment, the first printer head 402A and the secondprinter head 402B can both be linear printing stations and having areorientation mechanism located between the first printer head 402A andthe second printer head 402B to rotate the golf ball 400 by about 90degrees, or between 45 degrees and 135 degrees along a horizontal axis438 that is perpendicular to the axis of rotation 406.

In yet another embodiment, the first printer head 402A may be located ata rotational printing station and a plurality of printer heads, such asat least two, three, four, or five or more subsequent printer heads maybe located at linear printing stations.

In one embodiment, the digital encoder 420 can rotate the golf ball 400by between forty-five degrees to about ninety degrees about the verticalaxis of rotation 406 between the first printer head 402A and the secondprinter head 402B in order to print four images on a golf ball 400 atfirst distinct locations on the ball. These four images can also beprinted at linear printing stations. Additionally, the golf ball 400 canbe rotated along the horizontal axis 438 in between printing stations402A,402B to allow for the rotation of the golf ball along a horizontalaxis 438 that is perpendicular to the vertical axis of rotation 406. Therotation of the golf ball 400 about the horizontal axis 438 can beaccomplished by a ball rotation mechanism 440 located between theprinting stations 402A,402B which can be a mechanical mechanism with anencoder/decoder, a mechanical arm, a friction based contact member, orany other mechanical, electrical, or pneumatic device utilized to rotatea golf ball about the horizontal axis 438.

In FIG. 9, the ball printing heads are located on the right hand side ofthe linear directional movement 436, however, at any of the printingstations described herein, the printer head may be located on the leftside of the ball movement 436, above the ball, behind the ball, in frontof the ball, or below the ball. In one embodiment, the speed at whichthe ball 400 moves along the linear direction 436 can be 14 inches/secfor a 360 dpi printer resolution. If a 540 dpi printer resolution isutilized, the speed of the ball movement can be at 10 to 12 inches/sec.In one embodiment, the ratio of the printer resolution divided by thelinear direction speed can be between 10 dpi/(inches/sec) and 100dpi/(inches/sec), or preferably between 20 dip/(inches/sec) and 50dpi/(inches/sec). The speed at which balls are printed can be between 20and 300 balls per minute, or between 100 and 250 balls per minute.

In one embodiment, each linear printing station will require at leastfour printing heads for each image printed at the station. However, atthe rotational printing station, the four printing heads can be utilizedto print multiple images.

In one embodiment, the curing stations 418 include a UV pinningoperation having lamps with a power rating of between 0 and 20 watts orbetween 1.5 watts and 7.5 watts to partially cure the ink applied in theprevious printing station. In some embodiments, the UV curing can beaccomplished by mercury arc UV curing lamps or LED curing lamps. In oneembodiment, a UV pinning operation is used having lamps of a lowerwattage than a final UV curing lamp. For example, the pinning lamps mayhave a power rating of 5W or less while the final UV curing has a powerrating of more than 5 W or 5W to 15W. In certain embodiments, photoinitiators can be present in the ink to narrow the wavelength of lightin which curing occurs and thereby reducing ambient light contaminationduring the curing process. In one embodiment, the energy density of thecuring lamp is between 100 mJ/cm² and 5000 mJ/cm², or between 150 mJ/cm²and 3000 mJ/cm². In one embodiment, the pinning lamps have an energydensity that is less than the final curing lamps. For example, thepinning lamps may have an energy density of between 50 mJ/cm² to 200mJ/cm² while the final UV curing lamps are between 1 J/cm² and 5 J/cm².

FIG. 6 illustrates the same elements of FIG. 4 except that the printerhead has a curved surface 422 that provides a contour more closelymatching the general curvature of the golf ball 400. In someembodiments, the printer head curved surface has a radius of about 0.84″in order to match the radius of the golf ball 400 (excluding dimpledepth variations). The curved surface of the printer allows for the inkdroplets 408 to travel a more uniform distance between the golf ball 400and the printer head. A more uniform distance between the ink dispensingsurface and the surface of the golf ball can result in more consistentand higher quality images. FIG. 6 shows the trajectory of ink droplets408 is roughly perpendicular or orthogonal to the surface of the ball(excluding dimple depth variation) so that upper and lower distortionzones are effectively eliminated so that an intended image does not needto be modified in the printing software to accommodate for varyingdistances between the ball 400 and printer head 402.

FIG. 7 illustrates a putter assembly 700 of a grip 726, a shaft 704,head 706, heel 708, toe 710, and sole 712. The shaft 704 has a shaftaxis 714 and a fluted section length 724. The grip 726 has a grip length720. A printer head 702 is located adjacent to the shaft 704. Theprinter head 702 may be configured to be a single pass printer head or amultiple pass printer head. If a multiple pass printer head is utilized,all the parameters of printing and curing described in this applicationapply equally in each pass of the multiple pass printer application. Amultiple pass printer head 702 needs to make multiple movements acrossan object to completely print a desired image or pattern. In oneembodiment, the printer head 702 prints a solid color, pattern, or imagein the fluted section located within the fluted section length. In oneembodiment, the printer head 702 moves in a direction parallel to thesurface of the shaft that is being printed where the printer head 702 isangled by an angle between 0 and 10 degrees, 1 and 8 degrees, or 2 and 7degrees relative to the shaft axis 714. In another embodiment, theprinter head 702 moves parallel to the shaft axis 714. In oneembodiment, the printer head 702 moves in a first direction 718 towardthe grip and second direction 716 toward the club head 706. In oneembodiment, the printing of ink on the shaft 704 is applied while theprinter head is moving in the first direction 718 only and the printerhead 702 is reset without printing while moving in the second direction716. In another embodiment, the printer head 702 is moving in the seconddirection 716 while the ink is applied to the shaft and reset withoutany printing while moving in the first direction 718.

In yet another embodiment, the printer head 702 has a UV curing light728 connected to or located on the printer head 702 so that the ink ispre-cured in a UV pinning operation after each application of ink isapplied to the shaft 704. The UV pinning lamp parameters can beidentical to those described previously. The UV curing light 728 can bea final UV cure or a pre-cure UV pinning operation that occurs before afinal cure.

FIG. 8 illustrates a cross-sectional view take along section lines 8-8of FIG. 7. As shown in FIG. 8, there are six flutes 800 located in theshaft 704. Flutes 800 are indentations or recessed regions in the shaftthat extend longitudinally along the shaft axis 714. Each flute 800 isrelatively parallel with the adjacent flutes. In one embodiment, thenumber of flutes can be 1 to 20, 2 to 10, 3 to 7, or 4 to 6 located onthe shaft 704. The shaft 704 can be metal, composite, or plastic. In oneembodiment, only the flutes 800 have ink applied to the surface whilethe unpainted regions 802 are located between each of the printed flutes800. In one embodiment, the unprinted region 802 located between theprinted flutes 800 has a surface area that is less than the printedflutes 800 surface area. In one embodiment, the unprinted region 802within the cross-sectional view has a first outer surface contour length806 (measured two dimensionally as shown in the FIG. 8 and in a planeperpendicular to the shaft axis 714) that is less than a second outersurface contour length 804 of the flutes 800. In determining where theunprinted region 802 first outer contour length 806 ends and the secondouter contour length 804 in the flutes 800 begins when measuring thecontour length, a transition point having a radius of 5 mm ore more canbe the point of separation between unprinted region 802 and flutes 800when trying to determine the first and second outer contour length. Inone embodiment, a first outer contour length divided by a second outercontour is a Contour Ratio. The Contour Ratio can be less than 1,between 0.1 and 0.9, between 0.2 and 0.8, between 0.3 and 0.7, orbetween 0.4 and 0.6.

In one embodiment, the fluted section length 724 can be between 1 mm and375 mm, between 2 mm and 300 mm, between 5 mm and 290 mm, between 20 mmand 280 mm or between 25 mm and 200 mm. In one embodiment, the flutedsection length 724 can be shorter than the grip length 720. In anotherembodiment, the fluted section length 724 can be longer than the griplength 720. In one embodiment, the ratio between the fluted sectionlength 724 and the grip length 720 is between 0.05 and 1, between 0.1and 0.9, between 0.2 and 0.8, between 0.3 and 0.7, or between 0.4 and0.6.

The printing can occur before the shaft 704 of the putter is assembledand attached to the putter head 706. The shaft can be placed on a flatbed roller and the shaft can be rolled in a direction perpendicular tothe shaft axis as the printer head 702 makes multiple passes to printswathes of ink within the flutes 800. In one embodiment, the printswathes are the same width as the flute 800 lengths.

In another embodiment, a single polyurethane or polyurea composition maybe utilized rather than a first color-containing composition and asecond color-containing composition as described above. In particular, asingle color-containing polyurethane composition may be being used incombination with secondary application of either paint or ink forcreating the circumferential stripes. The terms “paint” and “ink” areused interchangeably throughout this specification. In instances wherethe term “ink” is used, it is understood that the term “paint” can alsobe substituted and visa versa. In general, “paint” is considered adispersion of insoluble opaque particles suspended in a clear mediumsuch as oil or water based mediums. In general, “ink” is a coloredorganic compound that is dissolved in a solvent or water. In oneembodiment, a urethane material is preferred over an ionomer covermaterial due to an increase in greenside spin of about 15%, higherdurability due to the shear resistance of the urethane thereby producinga higher quality colored golf ball.

For example, in the embodiment shown in FIG. 3A, a red polyurethanecover golf ball may be formed using the casting process outlined above.A wide white circumferential stripe is placed on the golf ball using oneof the stamping processes outlined above. A second black circumferentialstripe is applied centered on top of the white circumferential stripeusing similar stamping processes. If having the base urethane color inplace of the black stripe is preferred, during the white stripe stampingapplication a center portion of the stamping area could be left out tostamp two parallel white stripes during the same application.

In the embodiment shown in FIG. 3D, a white polyurethane cover ball isformed using the casting process outlined above. A center blackcircumferential stripe can be applied using any of the stampingprocesses outlined above. The ball could then be rotated 90° from theoriginal axis of rotation and a blue circle be applied with the stampingprocess. The ball would rotate 180° on the same axis of rotation and asecond blue circle could be stamped.

The embodiments shown in FIGS. 3A-3D can alternatively be made with afirst color-containing composition and a second color-containingcomposition as described above.

A series of clear coats, with or without additives, are applied to thegolf ball for durability and to achieve a gloss finish. Matte clear isalso an option. The printed images can be either under or over the clearcoat. In some embodiments, the circumferential stripes can be stamped orprinted over the clear coat layer.

The image, pole stamp, or pole marking ink may be UV curablecompositions. For example, the image ink may be a UV curable epoxy.Alternatively, the image, pole stamp, or pole marking ink may be curableby another mechanism such as heat. A clear coat (e.g., a UV curablecomposition) may be applied onto the cover layer surface and the images.In one exemplary embodiment, a paint can be applied to the cover layersurface of any color suitable for alignment.

Additional Golf Ball Components

The multi-color cover layers disclosed herein can be used on any golfball. In certain embodiments, the golf ball has a core and a cover layersurrounding the core. In certain embodiments, the golf ball has a core,at least one mantle layer, and a cover layer. The golf ball may be atwo-piece ball, a three-piece ball, a four-piece ball, a five-pieceball, or a six-piece ball.

The term “core” is intended to mean the elastic center of a golf ball.The core may be a unitary core having a center it may have one or more“core layers” of elastic material, which are usually made of rubberymaterial such as diene rubbers.

The term “cover layer” is intended to mean the outermost layer of thegolf ball; this is the layer that is directly in contact with paintand/or ink on the surface of the golf ball. If the cover consists of twoor more layers, only the outermost layer is designated the cover layer,and the remaining layers (excluding the outermost layer) are commonlydesignated intermediate layers as herein defined. The term “outer coverlayer” as used herein is used interchangeably with the term “coverlayer.”

The term “mantle layer” may be used interchangeably herein with theterms “intermediate layer” and is intended to mean any layer(s) in agolf ball disposed between the core and the outer cover layer. Should aball have more than one mantle layer, these may be distinguished as“inner intermediate layer” or “inner mantle layer” which terms may beused interchangeably to refer to the intermediate layer nearest the coreand furthest from the outer cover, as opposed to the “outer intermediatelayer” or “outer mantle layer” which terms may also be usedinterchangeably to refer to the intermediate layer furthest from thecore and closest to the outer cover, and if there are three intermediatelayers, these may be distinguished as “inner intermediate layer” or“inner mantle layer” which terms are used interchangeably to refer tothe intermediate or mantle layer nearest the core and furthest from theouter cover, as opposed to the “outer intermediate layer” or “outermantle layer” which terms are also used interchangeably to refer to theintermediate layer further from the core and closer to the outer cover,and as opposed to the “intermediate layer” or “intermediate mantlelayer” which terms are also used interchangeably to refer to theintermediate layer between the inner intermediate layer and the outerintermediate layer.

The cover layer can be used with golf balls of any desired size. “TheRules of Golf” by the USGA dictate that the size of a competition golfball must be at least 1.680 inches in diameter; however, golf balls ofany size can be used for leisure golf play. The preferred diameter ofthe golf balls is from about 1.680 inches to about 1.800 inches. Themore preferred diameter is from about 1.680 inches to about 1.760inches. A diameter of from about 1.680 inches to about 1.740 inches ismost preferred; however, diameters anywhere in the range of from 1.70 toabout 2.0 inches can be used. Oversize golf balls with diameters aboveabout 1.760 inches to as big as 2.75 inches are also within the scope ofthe invention.

Each of the mantle layers of the golf balls may have a thickness of lessthan 0.080 inch, more particularly less than 0.065 inch, and mostparticularly less than 0.055 inch.

In certain embodiments the inner mantle may have a material Shore Dhardness of 15 to 65, particularly 25 to 60, and more particularly 30 to58. The inner mantle may have a flexural modulus of 2 to 35,particularly 10 to 30, and more particularly 15 to 35, kpsi. Theintermediate mantle may have a flexural modulus of 10 to 50,particularly 25 to 50, and most particularly 25 to 40, kpsi, and amaterial Shore D hardness of 40 to 70, more particularly from 45 to 65,and most particularly from 50 to 60. The outer mantle may have amaterial Shore D hardness of 55 to 75, particularly 58 to 70, and moreparticularly 60 to 68. The outer mantle material may have a flexuralmodulus of 30 to 80, particularly 40 to 80, and most particularly 50 to75, kpsi. The core and mantle layer(s) may each include one or more ofthe following polymers.

Such polymers include synthetic and natural rubbers, thermoset polymerssuch as thermoset polyurethanes and thermoset polyureas, as well asthermoplastic polymers including thermoplastic elastomers such asunimodal ethylene/carboxylic acid copolymers, unimodalethylene/carboxylic acid/carboxylate terpolymers, bimodalethylene/carboxylic acid copolymers, bimodal ethylene/carboxylicacid/carboxylate terpolymers, unimodal ionomers, bimodal ionomers,modified unimodal ionomers, modified bimodal ionomers, thermoplasticpolyurethanes, thermoplastic polyureas, polyesters, copolyesters,polyamides, copolyamides, polycarbonates, polyolefins, polyphenyleneoxide, polyphenylene sulfide, diallyl phthalate polymer, polyimides,polyvinyl chloride, polyamide-ionomer, polyurethane-ionomer, polyvinylalcohol, polyarylate, polyacrylate, polyphenylene ether, impact-modifiedpolyphenylene ether, polystyrene, high impact polystyrene,acrylonitrile-butadiene-styrene copolymer styrene-acrylonitrile (SAN),acrylonitrile-styrene-acrylonitrile, styrene-maleic anhydride (S/MA)polymer, styrenic copolymer, functionalized styrenic copolymer,functionalized styrenic terpolymer, styrenic terpolymer, cellulosepolymer, liquid crystal polymer (LCP), ethylene-propylene-dieneterpolymer (EPDM), ethylene-vinyl acetate copolymers (EVA),ethylene-propylene copolymer, ethylene vinyl acetate, polyurea, andpolysiloxane and any and all combinations thereof. One example isParaloid EXL 2691A which is a methacrylate-butadiene-styrene (MBS)impact modifier available from Rohm & Haas Co.

More particularly, the synthetic and natural rubber polymers may includethe traditional rubber components used in golf ball applicationsincluding, both natural and synthetic rubbers, such ascis-1,4-polybutadiene, trans-1,4-polybutadiene, 1,2-polybutadiene,cis-polyisoprene, trans-polyisoprene, polychloroprene, polybutylene,styrene-butadiene rubber, styrene-butadiene-styrene block copolymer andpartially and fully hydrogenated equivalents, styrene-isoprene-styreneblock copolymer and partially and fully hydrogenated equivalents,nitrile rubber, silicone rubber, and polyurethane, as well as mixturesof these. Polybutadiene rubbers, especially 1,4-polybutadiene rubberscontaining at least 40 mol %, and more preferably 80 to 100 mol % ofcis-1,4 bonds, are preferred because of their high rebound resilience,moldability, and high strength after vulcanization. The polybutadienecomponent may be synthesized by using rare earth-based catalysts,nickel-based catalysts, or cobalt-based catalysts, conventionally usedin this field. Polybutadiene obtained by using lanthanum rareearth-based catalysts usually employ a combination of a lanthanum rareearth (atomic number of 57 to 71)-compound, but particularly preferredis a neodymium compound.

The 1,4-polybutadiene rubbers have a molecular weight distribution(Mw/Mn) of from about 1.2 to about 4.0, preferably from about 1.7 toabout 3.7, even more preferably from about 2.0 to about 3.5, mostpreferably from about 2.2 to about 3.2. The polybutadiene rubbers have aMooney viscosity (ML₁₊₄ (100° C.)) of from about 20 to about 80,preferably from about 30 to about 70, even more preferably from about 30to about 60, most preferably from about 35 to about 50. The term “Mooneyviscosity” used herein refers in each case to an industrial index ofviscosity as measured with a Mooney viscometer, which is a type ofrotary plastometer (see JIS K6300). This value is represented by thesymbol ML₁₊₄ (100° C.), wherein “M” stands for Mooney viscosity, “L”stands for large rotor (L-type), “1+4” stands for a pre-heating time of1 minute and a rotor rotation time of 4 minutes, and “100° C.” indicatesthat measurement was carried out at a temperature of 100° C.

Examples of 1,2-polybutadienes having differing tacticity, all of whichare suitable as unsaturated polymers for use in the presently disclosedcompositions, are atactic 1,2-polybutadiene, isotactic1,2-polybutadiene, and syndiotactic 1,2-polybutadiene. Syndiotactic1,2-polybutadiene having crystallinity suitable for use as anunsaturated polymer in the presently disclosed compositions arepolymerized from a 1,2-addition of butadiene. The presently disclosedgolf balls may include syndiotactic 1,2-polybutadiene havingcrystallinity and greater than about 70% of 1,2-bonds, more preferablygreater than about 80% of 1,2-bonds, and most preferably greater thanabout 90% of 1,2-bonds. Also, the 1,2-polybutadiene may have a meanmolecular weight between about 10,000 and about 350,000, more preferablybetween about 50,000 and about 300,000, more preferably between about80,000 and about 200,000, and most preferably between about 10,000 andabout 150,000. Examples of suitable syndiotactic 1,2-polybutadieneshaving crystallinity suitable for use in golf balls are sold under thetrade names RB810, RB820, and RB830 by JSR Corporation of Tokyo, Japan.These have more than 90% of 1,2 bonds, a mean molecular weight ofapproximately 120,000, and crystallinity between about 15% and about30%.

Examples of olefinic thermoplastic elastomers includemetallocene-catalyzed polyolefins, ethylene-octene copolymer,ethylene-butene copolymer, and ethylene-propylene copolymers all with orwithout controlled tacticity as well as blends of polyolefins havingethyl-propylene-non-conjugated diene terpolymer, rubber-based copolymer,and dynamically vulcanized rubber-based copolymer. Examples of theseinclude products sold under the trade names SANTOPRENE, DYTRON,VISAFLEX, and VYRAM by Advanced Elastomeric Systems of Houston, Tex.,and SARLINK by DSM of Haarlen, the Netherlands.

Examples of rubber-based thermoplastic elastomers include multiblockrubber-based copolymers, particularly those in which the rubber blockcomponent is based on butadiene, isoprene, or ethylene/butylene. Thenon-rubber repeating units of the copolymer may be derived from anysuitable monomers, including meth(acrylate) esters, such as methylmethacrylate and cyclohexylmethacrylate, and vinyl arylenes, such asstyrene. Examples of styrenic copolymers are resins manufactured byKraton Polymers (formerly of Shell Chemicals) under the trade namesKRATON D (for styrene-butadiene-styrene and styrene-isoprene-styrenetypes) and KRATON G (for styrene-ethylene-butylene-styrene andstyrene-ethylene-propylene-styrene types) and Kuraray under the tradename SEPTON. Examples of randomly distributed styrenic polymers includeparamethylstyrene-isobutylene (isobutene) copolymers developed byExxonMobil Chemical Corporation and styrene-butadiene random copolymersdeveloped by Chevron Phillips Chemical Corp.

Examples of copolyester thermoplastic elastomers include polyether esterblock copolymers, polylactone ester block copolymers, and aliphatic andaromatic dicarboxylic acid copolymerized polyesters. Polyether esterblock copolymers are copolymers comprising polyester hard segmentspolymerized from a dicarboxylic acid and a low molecular weight diol,and polyether soft segments polymerized from an alkylene glycol having 2to 10 atoms. Polylactone ester block copolymers are copolymers havingpolylactone chains instead of polyether as the soft segments discussedabove for polyether ester block copolymers. Aliphatic and aromaticdicarboxylic copolymerized polyesters are copolymers of an acidcomponent selected from aromatic dicarboxylic acids, such asterephthalic acid and isophthalic acid, and aliphatic acids having 2 to10 carbon atoms with at least one diol component, selected fromaliphatic and alicyclic diols having 2 to 10 carbon atoms. Blends ofaromatic polyester and aliphatic polyester also may be used for these.Examples of these include products marketed under the trade names HYTRELby E.I. DuPont de Nemours & Company, and SKYPEL by S.K. Chemicals ofSeoul, South Korea.

Examples of other thermoplastic elastomers suitable as additionalpolymer components include those having functional groups, such ascarboxylic acid, maleic anhydride, glycidyl, norbornene, and hydroxylfunctionalities. An example of these includes a block polymer having atleast one polymer block A comprising an aromatic vinyl compound and atleast one polymer block B comprising a conjugated diene compound, andhaving a hydroxyl group at the terminal block copolymer, or itshydrogenated product. An example of this polymer is sold under the tradename SEPTON HG-252 by Kuraray Company of Kurashiki, Japan. Otherexamples of these include: maleic anhydride functionalized triblockcopolymer consisting of polystyrene end blocks andpoly(ethylene/butylene), sold under the trade name KRATON FG 1901X byShell Chemical Company; maleic anhydride modified ethylene-vinyl acetatecopolymer, sold under the trade name FUSABOND by E.I. DuPont de Nemours& Company; ethylene-isobutyl acrylate-methacrylic acid terpolymer, soldunder the trade name NUCREL by E.I. DuPont de Nemours & Company;ethylene-ethyl acrylate-methacrylic anhydride terpolymer, sold under thetrade name BONDINE AX 8390 and 8060 by Sumitomo Chemical Industries;brominated styrene-isobutylene copolymers sold under the trade nameBROMO XP-50 by Exxon Mobil Corporation; and resins having glycidyl ormaleic anhydride functional groups sold under the trade name LOTADER byElf Atochem of Puteaux, France.

Another example of a polymer for making any of the mantle layers orcover layer is blend of a polyamide (which may be a polyamide asdescribed above) with a functional polymer modifier of the polyamide.The functional polymer modifier of the polyamide can include copolymersor terpolymers having a glycidyl group, hydroxyl group, maleic anhydridegroup or carboxylic group, collectively referred to as functionalizedpolymers. These copolymers and terpolymers may comprise an α-olefin.Examples of suitable α-olefins include ethylene, propylene, 1-butene,1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-l-petene,3-methyl-1-pentene, 1-octene, 1-decene-, 1-dodecene, 1-tetradecene,1-hexadecene, 1-octadecene, 1-eicocene, 1-dococene, 1-tetracocene,1-hexacocene, 1-octacocene, and 1-triacontene. One or more of theseα-olefins may be used.

Examples of suitable glycidyl groups in copolymers or terpolymers in thepolymeric modifier include esters and ethers of aliphatic glycidyl, suchas allylglycidylether, vinylglycidylether, glycidyl maleate anditaconatem glycidyl acrylate and methacrylate, and also alicyclicglycidyl esters and ethers, such as 2-cyclohexene-1-glycidylether,cyclohexene-4,5 diglyxidylcarboxylate, cyclohexene-4-glycidylcarboxylate, 5-norboenene-2-methyl-2-glycidyl carboxylate, andendocis-bicyclo(2,2,1)-5-heptene-2,3-diglycidyl dicarboxylate. Thesepolymers having a glycidyl group may comprise other monomers, such asesters of unsaturated carboxylic acid, for example, alkyl(meth)acrylatesor vinyl esters of unsaturated carboxylic acids. Polymers having aglycidyl group can be obtained by copolymerization or graftpolymerization with homopolymers or copolymers.

Examples of suitable terpolymers having a glycidyl group include LOTADERAX8900 and AX8920, marketed by Atofina Chemicals, ELVALOY marketed byE.I. Du Pont de Nemours & Co., and REXPEARL marketed by NipponPetrochemicals Co., Ltd. Additional examples of copolymers comprisingepoxy monomers and which are suitable for use within the scope of thepresent invention include styrene-butadiene-styrene block copolymers inwhich the polybutadiene block contains epoxy group, andstyrene-isoprene-styrene block copolymers in which the polyisopreneblock contains epoxy. Commercially available examples of these epoxyfunctional copolymers include ESBS A1005, ESBS A1010, ESBS A1020, ESBSAT018, and ESBS AT019, marketed by Daicel Chemical Industries, Ltd.

Examples of polymers or terpolymers incorporating a maleic anhydridegroup suitable for use within the scope of the present invention includemaleic anhydride-modified ethylene-propylene copolymers, maleicanhydride-modified ethylene-propylene-diene terpolymers, maleicanhydride-modified polyethylenes, maleic anhydride-modifiedpolypropylenes, ethylene-ethylacrylate-maleic anhydride terpolymers, andmaleic anhydride-indene-styrene-cumarone polymers. Examples ofcommercially available copolymers incorporating maleic anhydrideinclude: BONDINE, marketed by Sumitomo Chemical Co., such as BONDINEAX8390, an ethylene-ethyl acrylate-maleic anhydride terpolymer having acombined ethylene acrylate and maleic anhydride content of 32% byweight, and BONDINE TX TX8030, an ethylene-ethyl acrylate-maleicanhydride terpolymer having a combined ethylene acrylate and maleicanhydride content of 15% by weight and a maleic anhydride content of 1%to 4% by weight; maleic anhydride-containing LOTADER 3200, 3210, 6200,8200, 3300, 3400, 3410, 7500, 5500, 4720, and 4700, marketed by AtofinaChemicals; EXXELOR VA1803, a maleic anhydride-modifiedethylene-propylene copolymer having a maleic anhydride content of 0.7%by weight, marketed by Exxon Chemical Co.; and KRATON FG 1901X, a maleicanhydride functionalized triblock copolymer having polystyrene endblocksand poly(ethylene/butylene) midblocks, marketed by Shell Chemical.

Preferably the functional polymer component for blending with apolyamide is a maleic anhydride grafted polymers preferably maleicanhydride grafted polyolefins (for example, Exxellor VA1803).

Styrenic block copolymers are copolymers of styrene with butadiene,isoprene, or a mixture of the two. Additional unsaturated monomers maybe added to the structure of the styrenic block copolymer as needed forproperty modification of the resulting SBC/urethane copolymer. Thestyrenic block copolymer can be a diblock or a triblock styrenicpolymer. Examples of such styrenic block copolymers are described in,for example, U.S. Pat. No. 5,436,295 to Nishikawa et al. The styrenicblock copolymer can have any known molecular weight for such polymers,and it can possess a linear, branched, star, dendrimeric or combinationmolecular structure. The styrenic block copolymer can be unmodified byfunctional groups, or it can be modified by hydroxyl group, carboxylgroup, or other functional groups, either in its chain structure or atone or more terminus. The styrenic block copolymer can be obtained usingany common process for manufacture of such polymers. The styrenic blockcopolymers also may be hydrogenated using well-known methods to obtain apartially or fully saturated diene monomer block.

Other preferred materials suitable for use as additional polymers in thepresently disclosed compositions include polyester thermoplasticelastomers marketed under the tradename SKYPEL™ by SK Chemicals of SouthKorea, or diblock or triblock copolymers marketed under the tradenameSEPTON™ by Kuraray Corporation of Kurashiki, Japan, and KRATON™ byKraton Polymers Group of Companies of Chester, United Kingdom. Forexample, SEPTON HG 252 is a triblock copolymer, which has polystyreneend blocks and a hydrogenated polyisoprene midblock and has hydroxylgroups at the end of the polystyrene blocks. HG-252 is commerciallyavailable from Kuraray America Inc. (Houston, Tex.).

Additional other polymer components include polyalkenamers as described,for example, in US-2006-0166762-A1, which is incorporated herein byreference in its entirety. Examples of suitable polyalkenamer rubbersare polypentenamer rubber, polyheptenamer rubber, polyoctenamer rubber,polydecenamer rubber and polydodecenamer rubber. For further detailsconcerning polyalkenamer rubber, see Rubber Chem. & Tech., Vol. 47, page511-596, 1974, which is incorporated herein by reference. Polyoctenamerrubbers are commercially available from Huls AG of Marl, Germany, andthrough its distributor in the U.S., Creanova Inc. of Somerset, N.J.,and sold under the trademark VESTENAMER®. Two grades of the VESTENAMER®trans-polyoctenamer are commercially available: VESTENAMER 8012designates a material having a trans-content of approximately 80% (and acis-content of 20%) with a melting point of approximately 54° C.; andVESTENAMER 6213 designates a material having a trans-content ofapproximately 60% (cis-content of 40%) with a melting point ofapproximately 30° C. Both of these polymers have a double bond at everyeighth carbon atom in the ring.

If a polyalkenamer rubber is present, the polyalkenamer rubberpreferably contains from about 50 to about 99, preferably from about 60to about 99, more preferably from about 65 to about 99, even morepreferably from about 70 to about 90 percent of its double bonds in thetrans-configuration. The preferred form of the polyalkenamer has a transcontent of approximately 80%, however, compounds having other ratios ofthe cis- and trans-isomeric forms of the polyalkenamer can also beobtained by blending available products for use in making thecomposition.

The polyalkenamer rubber has a molecular weight (as measured by GPC)from about 10,000 to about 300,000, preferably from about 20,000 toabout 250,000, more preferably from about 30,000 to about 200,000, evenmore preferably from about 50,000 to about 150,000.

The polyalkenamer rubber has a degree of crystallization (as measured byDSC secondary fusion) from about 5 to about 70, preferably from about 6to about 50, more preferably from about from 6.5 to about 50%, even morepreferably from about from 7 to about 45%.

More preferably, the polyalkenamer rubber is a polymer prepared bypolymerization of cyclooctene to form a trans-polyoctenamer rubber as amixture of linear and cyclic macromolecules.

A further example of a polymer is a specialty propylene elastomer asdescribed, for example, in US 2007/0238552 A1, and incorporated hereinby reference in its entirety. A specialty propylene elastomer includes athermoplastic propylene-ethylene copolymer composed of a majority amountof propylene and a minority amount of ethylene. These copolymers have atleast partial crystallinity due to adjacent isotactic propylene units.Although not bound by any theory, it is believed that the crystallinesegments are physical crosslinking sites at room temperature, and athigh temperature (i.e., about the melting point), the physicalcrosslinking is removed and the copolymer is easy to process. Accordingto one embodiment, a specialty propylene elastomer includes at leastabout 50 mole % propylene co-monomer. Specialty propylene elastomers canalso include functional groups such as maleic anhydride, glycidyl,hydroxyl, and/or carboxylic acid. Suitable specialty propyleneelastomers include propylene-ethylene copolymers produced in thepresence of a metallocene catalyst. More specific examples of specialtypropylene elastomers are illustrated below. Specialty propyleneelastomers are commercially available under the tradename VISTAMAXX fromExxonMobil Chemical.

Another example of an additional polymer component includes thethermoplastic polyurethanes, which are the reaction product of a diol orpolyol and an isocyanate, with or without a chain extender. Isocyanatesused for making the urethanes encompass diisocyanates andpolyisocyanates. Examples of suitable isocyanates include the following:trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylenediisocyanate, hexamethylene diisocyanate, ethylene diisocyanate,diethylidene diisocyanate, propylene diisocyanate, butylenediisocyanate, bitolylene diisocyanate, tolidine isocyanate, isophoronediisocyanate, dimeryl diisocyanate, dodecane-1,12-diisocyanate,1,10-decamethylene diisocyanate, cyclohexylene-1,2-diisocyanate,1-chlorobenzene-2,4-diisocyanate, furfurylidene diisocyanate,2,4,4-trimethyl hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, dodecamethylene diisocyanate,1,3cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate,1,3-cyclobutane diisocyanate, 1,4-cyclohexane diisocyanate,4,4′-methylenebis(cyclohexyl isocyanate), 4,4′-methylenebis(phenylisocyanate), 1-methyl-2,4-cyclohexane diisocyanate,1-methyl-2,6-cyclohexane diisocyanate, 1,3-bis(isocyanato-methyl)cyclohexane,1,6-diisocyanato-2,2,4,4-tetra-methylhexane,1,6-diisocyanato-2,4,4-tetra-trimethylhexane,trans-cyclohexane-1,4-diisocyanate,3-isocyanato-methyl-3,5,5-trimethylcyclohexyl isocyanate,1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane, cyclohexylisocyanate, dicyclohexylmethane 4,4′-diisocyanate,1,4-bis(isocyanatomethyl) cyclohexane, m-phenylene diisocyanate,m-xylylene diisocyanate, m-tetramethylxylylene diisocyanate, p-phenylenediisocyanate, p,p′-biphenyl diisocyanate, 3,3′-dimethyl-4,4′-biphenylenediisocyanate, 3,3′-dimethoxy-4,4′-biphenylene diisocyanate,3,3′-diphenyl-4,4′-biphenylene diisocyanate, 4,4′-biphenylenediisocyanate, 3,3′-dichloro-4,4′-biphenylene diisocyanate,1,5-naphthalene diisocyanate, 4-chloro-1,3-phenylene diisocyanate,1,5-tetrahydronaphthalene diisocyanate, meta-xylene diisocyanate,2,4-toluene diisocyanate, 2,4′-diphenylmethane diisocyanate,2,4-chlorophenylene diisocyanate, 4,4′-diphenylmethane diisocyanate,p,p′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate,2,6-tolylene diisocyanate, 2,2-diphenylpropane-4,4′-diisocyanate,4,4′-toluidine diisocyanate, dianisidine diisocyanate, 4,4′-diphenylether diisocyanate, 1, 3-xylylene diisocyanate, 1,4-naphthylenediisocyanate, azobenzene-4,4′-diisocyanate, diphenylsulfone-4,4′-diisocyanate, triphenylmethane 4,4′, 4″-triisocyanate,isocyanatoethyl methacrylate,3-isopropenyl-α,α-dimethylbenzyl-isocyanate, dichlorohexamethylenediisocyanate, ω, ω′-diisocyanato-1,4-diethylbenzene, polymethylenepolyphenylene polyisocyanate, polybutylene diisocyanate, isocyanuratemodified compounds, and carbodiimide modified compounds, as well asbiuret modified compounds of the above polyisocyanates. Each isocyanatemay be used either alone or in combination with one or more otherisocyanates. These isocyanate mixtures can include triisocyanates, suchas biuret of hexamethylene diisocyanate and triphenylmethanetriisocyanate, and polyisocyanates, such as polymeric diphenylmethanediisocyanate.

Polyols used for making the polyurethane in the copolymer includepolyester polyols, polyether polyols, polycarbonate polyols andpolybutadiene polyols. Polyester polyols are prepared by condensation orstep-growth polymerization utilizing diacids. Primary diacids forpolyester polyols are adipic acid and isomeric phthalic acids. Adipicacid is used for materials requiring added flexibility, whereas phthalicanhydride is used for those requiring rigidity. Some examples ofpolyester polyols include poly(ethylene adipate) (PEA), poly(diethyleneadipate) (PDA), poly(propylene adipate) (PPA), poly(tetramethyleneadipate) (PBA), poly(hexamethylene adipate) (PHA), poly(neopentyleneadipate) (PNA), polyols composed of 3-methyl-1,5-pentanediol and adipicacid, random copolymer of PEA and PDA, random copolymer of PEA and PPA,random copolymer of PEA and PBA, random copolymer of PHA and PNA,caprolactone polyol obtained by the ring-opening polymerization ofε-caprolactone, and polyol obtained by opening the ring ofβ-methyl-δ-valerolactone with ethylene glycol can be used either aloneor in a combination thereof. Additionally, polyester polyol may becomposed of a copolymer of at least one of the following acids and atleast one of the following glycols. The acids include terephthalic acid,isophthalic acid, phthalic anhydride, oxalic acid, malonic acid,succinic acid, pentanedioic acid, hexanedioic acid, octanedioic acid,nonanedioic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioicacid, dimer acid (a mixture), ρ-hydroxybenzoate, trimellitic anhydride,E-caprolactone, and β-methyl-δ-valerolactone. The glycols includeethylene glycol, propylene glycol, butylene glycol, pentylene glycol,1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentylene glycol,polyethylene glycol, polytetramethylene glycol, 1,4-cyclohexanedimethanol, pentaerythritol, and 3-methyl-1,5-pentanediol.

Polyether polyols are prepared by the ring-opening additionpolymerization of an alkylene oxide (e.g. ethylene oxide and propyleneoxide) with an initiator of a polyhydric alcohol (e.g. diethyleneglycol), which is an active hydride. Specifically, polypropylene glycol(PPG), polyethylene glycol (PEG) or propylene oxide-ethylene oxidecopolymer can be obtained. Polytetramethylene ether glycol (PTMG) isprepared by the ring-opening polymerization of tetrahydrofuran, producedby dehydration of 1,4-butanediol or hydrogenation of furan.Tetrahydrofuran can form a copolymer with alkylene oxide. Specifically,tetrahydrofuran-propylene oxide copolymer or tetrahydrofuran-ethyleneoxide copolymer can be formed. A polyether polyol may be used eitheralone or in a mixture.

Polycarbonate polyol is obtained by the condensation of a known polyol(polyhydric alcohol) with phosgene, chloroformic acid ester, dialkylcarbonate or diallyl carbonate. A particularly preferred polycarbonatepolyol contains a polyol component using 1,6-hexanediol, 1,4-butanediol,1,3-butanediol, neopentylglycol or 1,5-pentanediol. A polycarbonatepolyol can be used either alone or in a mixture.

Polybutadiene polyol includes liquid diene polymer containing hydroxylgroups, and an average of at least 1.7 functional groups, and may becomposed of diene polymer or diene copolymer having 4 to 12 carbonatoms, or a copolymer of such diene with addition to polymerizableα-olefin monomer having 2 to 2.2 carbon atoms. Specific examples includebutadiene homopolymer, isoprene homopolymer, butadiene-styrenecopolymer, butadiene-isoprene copolymer, butadiene-acrylonitrilecopolymer, butadiene-2-ethyl hexyl acrylate copolymer, andbutadiene-n-octadecyl acrylate copolymer. These liquid diene polymerscan be obtained, for example, by heating a conjugated diene monomer inthe presence of hydrogen peroxide in a liquid reactant. A polybutadienepolyol can be used either alone or in a mixture.

As stated above, the urethane also may incorporate chain extenders.Non-limiting examples of these extenders include polyols, polyaminecompounds, and mixtures of these. Polyol extenders may be primary,secondary, or tertiary polyols. Specific examples of monomers of thesepolyols include: trimethylolpropane (TMP), ethylene glycol,1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol,propylene glycol, dipropylene glycol, 1,2-butanediol, 1,3-butanediol,2,3-butanediol, 1,2-pentanediol, 2,3-pentanediol, 2,5-hexanediol,2,4-hexanediol, 2-ethyl-1,3-hexanediol, cyclohexanediol, and2-ethyl-2-(hydroxymethyl)-1,3-propanediol.

Suitable polyamines that may be used as chain extenders include primary,secondary and tertiary amines; polyamines have two or more amines asfunctional groups. Examples of these include: aliphatic diamines, suchas tetramethylenediamine, pentamethylenediamine, hexamethylenediamine;alicyclic diamines, such as 3,3′-dimethyl-4,4′-diamino-dicyclohexylmethane; or aromatic diamines, such as 4,4′-methylenebis-2-chloroaniline, 2,2′, 3,3′-tetrachloro-4,4′-diaminophenyl methane,p,p′-methylenedianiline, p-phenylenediamine or 4,4′-diaminodiphenyl; and2,4,6-tris(dimethylaminomethyl) phenol. Aromatic diamines have atendency to provide a stiffer product than aliphatic or cycloaliphaticdiamines. A chain extender may be used either alone or in a mixture.

Polyurethanes or polyureas typically are prepared by reacting adiisocyanate with a polyol (in the case of polyurethanes) or with apolyamine (in the case of a polyurea). Thermoplastic polyurethanes orpolyureas may consist solely of this initial mixture or may be furthercombined with a chain extender to vary properties such as hardness ofthe thermoplastic. Thermoset polyurethanes or polyureas typically areformed by the reaction of a diisocyanate and a polyol or polyaminerespectively, and an additional crosslinking agent to crosslink or curethe material to result in a thermoset.

In what is known as a one-shot process, the three reactants,diisocyanate, polyol or polyamine, and optionally a chain extender or acuring agent, are combined in one step. Alternatively, a two-stepprocess may occur in which the first step involves reacting thediisocyanate and the polyol (in the case of polyurethane) or thepolyamine (in the case of a polyurea) to form a so-called prepolymer, towhich can then be added either the chain extender or the curing agent.This procedure is known as the prepolymer process.

In addition, although depicted as discrete component packages as above,it is also possible to control the degree of crosslinking, and hence thedegree of thermoplastic or thermoset properties in a final composition,by varying the stoichiometry not only of the diisocyanate-to-chainextender or curing agent ratio, but also the initialdiisocyanate-to-polyol or polyamine ratio. Of course in the prepolymerprocess, the initial diisocyanate-to-polyol or polyamine ratio is fixedon selection of the required prepolymer.

Finally, in addition to discrete thermoplastic or thermoset materials,it also is possible to modify a thermoplastic polyurethane or polyureacomposition by introducing materials in the composition that undergosubsequent curing after molding the thermoplastic to provide propertiessimilar to those of a thermoset. For example, Kim in U.S. Pat. No.6,924,337, the entire contents of which are hereby incorporated byreference, discloses a thermoplastic urethane or urea compositionoptionally comprising chain extenders and further comprising a peroxideor peroxide mixture, which can then undergo post curing to result in athermoset.

Also, Kim et al. in U.S. Pat. No. 6,939,924, the entire contents ofwhich are hereby incorporated by reference, discloses a thermoplasticurethane or urea composition, optionally also comprising chainextenders, that is prepared from a diisocyanate and a modified orblocked diisocyanate which unblocks and induces further cross-linkingpost extrusion. The modified isocyanate preferably is selected from thegroup consisting of: isophorone diisocyanate (IPDI)-based uretdione-typecrosslinker; a combination of a uretdione adduct of IPDI and a partiallye-caprolactam-modified IPDI; a combination of isocyanate adductsmodified by e-caprolactam and a carboxylic acid functional group; acaprolactam-modified Desmodur diisocyanate; a Desmodur diisocyanatehaving a 3,5-dimethyl pyrazole modified isocyanate; or mixtures ofthese.

Finally, Kim et al. in U.S. Pat. No. 7,037,985 B2, the entire contentsof which are hereby incorporated by reference, discloses thermoplasticurethane or urea compositions further comprising a reaction product of anitroso compound and a diisocyanate or a polyisocyanate. The nitrosoreaction product has a characteristic temperature at which it decomposesto regenerate the nitroso compound and diisocyanate or polyisocyanate.Thus, by judicious choice of the post-processing temperature, furthercrosslinking can be induced in the originally thermoplastic compositionto provide thermoset-like properties.

Any isocyanate available to one of ordinary skill in the art is suitablefor use according to the invention. Isocyanates for use with the presentinvention include, but are not limited to, aliphatic, cycloaliphatic,aromatic aliphatic, aromatic, any derivatives thereof, and combinationsof these compounds having two or more isocyanate (NCO) groups permolecule. As used herein, aromatic aliphatic compounds should beunderstood as those containing an aromatic ring, wherein the isocyanategroup is not directly bonded to the ring. One example of an aromaticaliphatic compound is a tetramethylene diisocyanate (TMXDI). Theisocyanates may be organic polyisocyanate-terminated prepolymers, lowfree isocyanate prepolymer, and mixtures thereof. Theisocyanate-containing reactable component also may include anyisocyanate-functional monomer, dimer, trimer, or polymeric adductthereof, prepolymer, quasi-prepolymer, or mixtures thereof.Isocyanate-functional compounds may include monoisocyanates orpolyisocyanates that include any isocyanate functionality of two ormore.

Suitable isocyanate-containing components include diisocyanates havingthe generic structure: O=C=N—R—N═C═O, where R preferably is a cyclic,aromatic, or linear or branched hydrocarbon moiety containing from about1 to about 50 carbon atoms. The isocyanate also may contain one or morecyclic groups or one or more phenyl groups. When multiple cyclic oraromatic groups are present, linear and/or branched hydrocarbonscontaining from about 1 to about 10 carbon atoms can be present asspacers between the cyclic or aromatic groups. In some cases, the cyclicor aromatic group(s) may be substituted at the 2-, 3-, and/or4-positions, or at the ortho-, meta-, and/or para-positions,respectively. Substituted groups may include, but are not limited to,halogens, primary, secondary, or tertiary hydrocarbon groups, or amixture thereof.

Examples of isocyanates that can be used with the present inventioninclude, but are not limited to, substituted and isomeric mixturesincluding 2,2′-, 2,4′-, and 4,4′-diphenylmethane diisocyanate (MDI);3,3′-dimethyl-4,4′-biphenylene diisocyanate (TODI); toluene diisocyanate(TDI); polymeric MDI; carbodiimide-modified liquid 4,4′-diphenylmethanediisocyanate; para-phenylene diisocyanate (PPDI); meta-phenylenediisocyanate (MPDI); triphenyl methane-4,4′- and triphenylmethane-4,4″-triisocyanate; naphthylene-1,5-diisocyanate; 2,4′-, 4,4′-,and 2,2-biphenyl diisocyanate; polyphenylene polymethylenepolyisocyanate (PMDI) (also known as polymeric PMDI); mixtures of MDIand PMDI; mixtures of PMDI and TDI; ethylene diisocyanate;propylene-1,2-diisocyanate; trimethylene diisocyanate; butylenesdiisocyanate; bitolylene diisocyanate; toluidine diisocyanate;tetramethylene-1,2-diisocyanate; tetramethylene-1,3-diisocyanate;tetramethylene-1,4-diisocyanate; pentamethylenediisocyanate;1,6-hexamethylene diisocyanate (HDI); octamethylenediisocyanate; decamethylene diisocyanate; 2,2,4-trimethylhexamethylenediisocyanate; 2,4,4-trimethylhexamethylene diisocyanate;dodecane-1,12-diisocyanate; dicyclohexylmethane diisocyanate;cyclobutane-1,3-diisocyanate; cyclohexane-1,2-diisocyanate;cyclohexane-1,3-diisocyanate; cyclohexane-1,4-diisocyanate; diethylidenediisocyanate; methylcyclohexylene diisocyanate (HTDI);2,4-methylcyclohexane diisocyanate; 2,6-methylcyclohexane diisocyanate;4,4′-dicyclohexyl diisocyanate; 2,4′-dicyclohexyl diisocyanate;1,3,5-cyclohexane triisocyanate; isocyanatomethylcyclohexane isocyanate;1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane;isocyanatoethylcyclohexane isocyanate; bis(isocyanatomethyl)-cyclohexanediisocyanate; 4,4′-bis(isocyanatomethyl) dicyclohexane;2,4′-bis(isocyanatomethyl) dicyclohexane; isophorone diisocyanate(IPDI); dimeryl diisocyanate, dodecane-1,12-diisocyanate,1,10-decamethylene diisocyanate, cyclohexylene-1,2-diisocyanate,1,10-decamethylene diisocyanate, 1-chlorobenzene-2,4-diisocyanate,furfurylidene diisocyanate, 2,4,4-trimethyl hexamethylene diisocyanate,2,2,4-trimethyl hexamethylene diisocyanate, dodecamethylenediisocyanate, 1,3-cyclopentane diisocyanate, 1,3-cyclohexanediisocyanate, 1,3-cyclobutane diisocyanate, 1,4-cyclohexanediisocyanate, 4,4′-methylenebis(cyclohexyl isocyanate),4,4′-methylenebis(phenyl isocyanate), 1-methyl-2,4-cyclohexanediisocyanate, 1-methyl-2,6-cyclohexane diisocyanate, 1,3-bis(isocyanato-methyl)cyclohexane,1,6-diisocyanato-2,2,4,4-tetra-methylhexane,1,6-diisocyanato-2,4,4-tetra-trimethylhexane,trans-cyclohexane-1,4-diisocyanate,3-isocyanato-methyl-3,5,5-trimethylcyclo-hexyl isocyanate,1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane, cyclohexylisocyanate, dicyclohexylmethane 4,4′-diisocyanate,1,4-bis(isocyanatomethyl) cyclohexane, m-phenylene diisocyanate,m-xylylene diisocyanate, m-tetramethylxylylene diisocyanate, p-phenylenediisocyanate, p,p′-biphenyl diisocyanate, 3,3′-dimethyl-4,4′-biphenylenediisocyanate, 3,3′-dimethoxy-4,4′-biphenylene diisocyanate,3,3′-diphenyl-4,4′-biphenylene diisocyanate, 4,4′-biphenylenediisocyanate, 3,3′-dichloro-4,4′-biphenylene diisocyanate,1,5-naphthalene diisocyanate, 4-chloro-1,3-phenylene diisocyanate,1,5-tetrahydronaphthalene diisocyanate, metaxylene diisocyanate,2,4-toluene diisocyanate, 2,4′-diphenylmethane diisocyanate,2,4-chlorophenylene diisocyanate, 4,4′-diphenylmethane diisocyanate,p,p′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate,2,6-tolylene diisocyanate, 2,2-diphenylpropane-4,4′-diisocyanate,4,4′-toluidine diisocyanate, dianidine diisocyanate, 4,4′-diphenyl etherdiisocyanate, 1, 3-xylylene diisocyanate, 1,4-naphthylene diisocyanate,azobenzene-4,4′-diisocyanate, diphenyl sulfone-4,4′-diisocyanate,triphenylmethane 4,4′, 4″-triisocyanate, isocyanatoethyl methacrylate,3-isopropenyl-α,α-dimethylbenzyl-isocyanate, dichlorohexamethylenediisocyanate, ω, ω′-diisocyanato-1,4-diethylbenzene, polymethylenepolyphenylene polyisocyanate, isocyanurate modified compounds, andcarbodiimide modified compounds, as well as biuret modified compounds ofthe above polyisocyanates. These isocyanates may be used either alone orin combination. These combination isocyanates include triisocyanates,such as biuret of hexamethylene diisocyanate and triphenylmethanetriisocyanates, and polyisocyanates, such as polymeric diphenylmethanediisocyanate.triisocyanate of HDI; triisocyanate of2,2,4-trimethyl-1,6-hexane diisocyanate (TMDI); 4,4′-dicyclohexylmethanediisocyanate (H₁₂MDI); 2,4-hexahydrotoluene diisocyanate;2,6-hexahydrotoluene diisocyanate; 1,2-, 1,3-, and 1,4-phenylenediisocyanate; aromatic aliphatic isocyanate, such as 1,2-, 1,3-, and1,4-xylene diisocyanate; meta-tetramethylxylene diisocyanate (m-TMXDI);para-tetramethylxylene diisocyanate (p-TMXDI); trimerized isocyanurateof any polyisocyanate, such as isocyanurate of toluene diisocyanate,trimer of diphenylmethane diisocyanate, trimer of tetramethylxylenediisocyanate, isocyanurate of hexamethylene diisocyanate, and mixturesthereof, dimerized uretdione of any polyisocyanate, such as uretdione oftoluene diisocyanate, uretdione of hexamethylene diisocyanate, andmixtures thereof; modified polyisocyanate derived from the aboveisocyanates and polyisocyanates; and mixtures thereof.

In view of the advantages of injection molding versus the more complexcasting process, under some circumstances it is advantageous to haveformulations capable of curing as a thermoset but only within aspecified temperature range above that of the typical injection moldingprocess. This allows parts, such as golf ball cover layers, to beinitially injection molded, followed by subsequent processing at highertemperatures and pressures to induce further crosslinking and curing,resulting in thermoset properties in the final part. Such an initiallyinjection moldable composition is thus called a post curable urethane orurea composition. In one exemplary embodiment, a post curable urethaneor rea can be sued for the multi-color cover layer.

If a post curable urethane composition is required, a modified orblocked diisocyanate which subsequently unblocks and induces furthercross-linking post extrusion may be included in the diisocyanatestarting material. Modified isocyanates used for making thepolyurethanes of the present invention generally are defined as chemicalcompounds containing isocyanate groups that are not reactive at roomtemperature, but that become reactive once they reach a characteristictemperature. The resulting isocyanates can act as crosslinking agents orchain extenders to form crosslinked polyurethanes. The degree ofcrosslinking is governed by type and concentration of modifiedisocyanate presented in the composition. The modified isocyanate used inthe composition preferably is selected, in part, to have acharacteristic temperature sufficiently high such that the urethane inthe composition will retain its thermoplastic behavior during initialprocessing (such as injection molding). If a characteristic temperatureis too low, the composition crosslinks before processing is completed,leading to process difficulties. The modified isocyanate preferably isselected from isophorone diisocyanate (IPDI)-based uretdione-typecrosslinker; a combination of a uretdione adduct of IPDI and a partiallye-caprolactam-modified IPDI; a combination of isocyanate adductsmodified by e-caprolactam and a carboxylic acid functional group; acaprolactam-modified Desmodur diisocyanate; a Desmodur diisocyanatehaving a 3,5-dimethyl pyrazole modified isocyanate; or mixtures ofthese. Particular preferred examples of modified isocyanates includethose marketed under the trade name CRELAN by Bayer Corporation.Examples of these include: CRELAN TP LS 2147; CRELAN NI 2; isophoronediisocyanate (IPDI)-based uretdione-type crosslinker, such as CRELAN VPLS 2347; a combination of a uretdione adduct of IPDI and a partiallye-caprolactam-modified IPDI, such as CRELAN VP LS 2386; a combination ofisocyanate adducts modified by e-caprolactam and a carboxylic acidfunctional group, such as CRELAN VP LS 2181/1; a caprolactam-modifiedDesmodur diisocyanate, such as CRELAN NWS; and a Desmodur diisocyanatehaving a 3,5-dimethyl pyrazole modified isocyanate, such as CRELAN XP7180. These modified isocyanates may be used either alone or incombination. Such modified diisocyanates are described in more detail inU.S. Pat. No. 6,939,924, the entire contents of which are herebyincorporated by reference.

As an alternative if a post curable polyurethane or polyurea compositionis required, the diisocyanate may further comprise reaction product of anitroso compound and a diisocyanate or a polyisocyanate. The reactionproduct has a characteristic temperature at which it decomposesregenerating the nitroso compound and diisocyanate or polyisocyanate,which can, by judicious choice of the post processing temperature, inturn induce further crosslinking in the originally thermoplasticcomposition resulting in thermoset-like properties. Such nitrosocompounds are described in more detail in U.S. Pat. No. 7,037,985 B2,the entire contents of which are hereby incorporated by reference.

Any polyol now known or hereafter developed is suitable for useaccording to the invention. Polyols suitable for use in the presentinvention include, but are not limited to, polyester polyols, polyetherpolyols, polycarbonate polyols and polydiene polyols such aspolybutadiene polyols.

Polyester polyols are prepared by condensation or step-growthpolymerization utilizing diacids. Primary diacids for polyester polyolsare adipic acid and isomeric phthalic acids. Adipic acid is used formaterials requiring added flexibility, whereas phthalic anhydride isused for those requiring rigidity. Some examples of polyester polyolsinclude poly(ethylene adipate) (PEA), poly(diethylene adipate) (PDA),poly(propylene adipate) (PPA), poly(tetramethylene adipate) (PB A),poly(hexamethylene adipate) (PHA), poly(neopentylene adipate) (PNA),polyols composed of 3-methyl-1,5-pentanediol and adipic acid, randomcopolymer of PEA and PDA, random copolymer of PEA and PPA, randomcopolymer of PEA and PBA, random copolymer of PHA and PNA, caprolactonepolyol obtained by the ring-opening polymerization of ε-caprolactone,and polyol obtained by opening the ring of β-methyl-δ-valerolactone withethylene glycol can be used either alone or in a combination thereof.Additionally, polyester polyol may be composed of a copolymer of atleast one of the following acids and at least one of the followingglycols. The acids include terephthalic acid, isophthalic acid, phthalicanhydride, oxalic acid, malonic acid, succinic acid, pentanedioic acid,hexanedioic acid, octanedioic acid, nonanedioic acid, adipic acid,azelaic acid, sebacic acid, dodecanedioic acid, dimer acid (a mixture),p-hydroxybenzoate, trimellitic anhydride, ε-caprolactone, andβ-methyl-δ-valerolactone. The glycols includes ethylene glycol,propylene glycol, butylene glycol, pentylene glycol, 1,4-butanediol,1,5-pentanediol, 1,6-hexanediol, neopentylene glycol, polyethyleneglycol, polytetramethylene glycol, 1,4-cyclohexane dimethanol,pentaerythritol, and 3-methyl-1,5-pentanediol.

Polyether polyols are prepared by the ring-opening additionpolymerization of an alkylene oxide (e.g. ethylene oxide and propyleneoxide) with an initiator of a polyhydric alcohol (e.g. diethyleneglycol), which is an active hydride. Specifically, polypropylene glycol(PPG), polyethylene glycol (PEG) or propylene oxide-ethylene oxidecopolymer can be obtained. Polytetramethylene ether glycol (PTMG) isprepared by the ring-opening polymerization of tetrahydrofuran, producedby dehydration of 1,4-butanediol or hydrogenation of furan.Tetrahydrofuran can form a copolymer with alkylene oxide. Specifically,tetrahydrofuran-propylene oxide copolymer or tetrahydrofuran-ethyleneoxide copolymer can be formed. The polyether polyol may be used eitheralone or in a combination.

Polycarbonate polyol is obtained by the condensation of a known polyol(polyhydric alcohol) with phosgene, chloroformic acid ester, dialkylcarbonate or diallyl carbonate. Particularly preferred polycarbonatepolyols contain a polyol component using 1,6-hexanediol, 1,4-butanediol,1,3-butanediol, neopentylglycol or 1,5-pentanediol. Polycarbonatepolyols can be used either alone or in a combination with other polyols.

Polydiene polyols include liquid diene polymer containing hydroxylgroups having an average of at least 1.7 functional groups, and maycomprise diene polymers or diene copolymers having from about 4 to about12 carbon atoms, or a copolymer of such diene with addition topolymerizable α-olefin monomer having 2 to 2.2 carbon atoms. Specificexamples include butadiene homopolymer, isoprene homopolymer,butadiene-styrene copolymer, butadiene-isoprene copolymer,butadiene-acrylonitrile copolymer, butadiene-2-ethyl hexyl acrylatecopolymer, and butadiene-n-octadecyl acrylate copolymer. These liquiddiene polymers can be obtained, for example, by heating a conjugateddiene monomer in the presence of hydrogen peroxide in a liquid reactant.

Polybutadiene polyol includes liquid diene polymer containing hydroxylgroups having an average of at least 1.7 functional groups, and may becomposed of diene polymer or diene copolymer having 4 to 12 carbonatoms, or a copolymer of such diene with addition to polymerizableα-olefin monomer having 2 to 2.2 carbon atoms. Specific examples includebutadiene homopolymer, isoprene homopolymer, butadiene-styrenecopolymer, butadiene-isoprene copolymer, butadiene-acrylonitrilecopolymer, butadiene-2-ethyl hexyl acrylate copolymer, andbutadiene-n-octadecyl acrylate copolymer. These liquid diene polymerscan be obtained, for example, by heating a conjugated diene monomer inthe presence of hydrogen peroxide in a liquid reactant

Any polyamine available to one of ordinary skill in the polyurethane artis suitable for use according to the disclosure herein. Polyaminessuitable for use include, but are not limited to, amine-terminatedcompounds typically are selected from amine-terminated hydrocarbons,amine-terminated polyethers, amine-terminated polyesters,amine-terminated polycaprolactones, amine-terminated polycarbonates,amine-terminated polyamides, and mixtures thereof. The amine-terminatedcompound may be a polyether amine selected from polytetramethylene etherdiamines, polyoxypropylene diamines, poly(ethylene oxide cappedoxypropylene) ether diamines, triethyleneglycoldiamines, propyleneoxide-based triamines, trimethylolpropane-based triamines,glycerin-based triamines, and mixtures thereof.

Diisocyanate and polyol or polyamine components may be combined to forma prepolymer prior to reaction with a chain extender or curing agent.Any such prepolymer combination is suitable for use in the presentinvention. Commercially available prepolymers include LFH580, LFH120,LFH710, LFH1570, LF930A, LF950A, LF601D, LF751D, LFG963A, LFG640D.

One preferred prepolymer is a toluene diisocyanate prepolymer withpolypropylene glycol. Such polypropylene glycol terminated toluenediisocyanate prepolymers are available from Uniroyal Chemical Company ofMiddlebury, Conn., under the trade name ADIPRENE® LFG963A and LFG640D.Most preferred prepolymers are the polytetramethylene ether glycolterminated toluene diisocyanate prepolymers including those availablefrom Uniroyal Chemical Company of Middlebury, Conn., under the tradename ADIPRENE® LF930A, LF950A, LF601D, and LF751D.

In one embodiment, the number of free NCO groups in the urethane or ureaprepolymer may be less than about 14 percent. Preferably the urethane orurea prepolymer has from about 3 percent to about 11 percent, morepreferably from about 4 to about 9.5 percent, and even more preferablyfrom about 3 percent to about 9 percent, free NCO on an equivalentweight basis.

Polyol chain extenders or curing agents may be primary, secondary, ortertiary polyols. Non-limiting examples of monomers of these polyolsinclude: trimethylolpropane (TMP), ethylene glycol, 1,3-propanediol,1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, propylene glycol,dipropylene glycol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol,1,2-pentanediol, 2,3-pentanediol, 2,5-hexanediol, 2,4-hexanediol,2-ethyl-1,3-hexanediol, cyclohexanediol, and2-ethyl-2-(hydroxymethyl)-1,3-propanediol.

Diamines and other suitable polyamines may be added to the compositionsto function as chain extenders or curing agents. These include primary,secondary and tertiary amines having two or more amines as functionalgroups. Exemplary diamines include aliphatic diamines, such astetramethylenediamine, pentamethylenediamine, hexamethylenediamine;alicyclic diamines, such as 3,3′-dimethyl-4,4′-diamino-dicyclohexylmethane; or aromatic diamines, such asdiethyl-2,4-toluenediamine-4,4″-methylenebis-(3-chloro,2,6-diethyl)-aniline(available from Air Products and Chemicals Inc., of Allentown, Pa.,under the trade name LONZACURE®), 3,3′-dichlorobenzidene;3,3′-dichloro-4,4′-diaminodiphenyl methane (MOCA);N,N,N′,N′-tetrakis(2-hydroxypropyl)ethylenediamine,3,5-dimethylthio-2,4-toluenediamine;3,5-dimethylthio-2,6-toluenediamine; N,N′-dialkyldiamino diphenylmethane; trimethylene-glycol-di-p-aminobenzoate;polytetramethyleneoxide-di-p-aminobenzoate, 4,4′-methylenebis-2-chloroaniline, 2,2′, 3,3′-tetrachloro-4,4′-diamino-phenyl methane,p,p′-methylenedianiline, p-phenylenediamine or 4,4′-diaminodiphenyl; and2,4,6-tris(dimethylaminomethyl) phenol.

Further examples include ethylene diamine; 1-methyl-2,6-cyclohexyldiamine; 2,2,4- and 2,4,4-trimethyl-1,6-hexanediamine;4,4′-bis-(sec-butylamino)-dicyclohexylmethane;1,4-bis-(sec-butylamino)-cyclohexane;1,2-bis-(sec-butylamino)-cyclohexane; derivatives of4,4′-bis-(sec-butylamino)-dicyclohexylmethane; 4,4′-dicyclohexylmethanediamine; 1,4-cyclohexane-bis-(methylamine);1,3-cyclohexane-bis-(methylamine); diethylene glycol bis-(aminopropyl)ether; 2-methylpentamethylene-diamine; diaminocyclohexane; diethylenetriamine; triethylene tetramine; tetraethylene pentamine; propylenediamine; 1,3-diaminopropane; dimethylamino propylamine; diethylaminopropylamine; imido-(bis-propylamine); monoethanolamine, diethanolamine;triethanolamine; monoisopropanolamine, diisopropanolamine;isophoronediamine; and mixtures thereof.

Aromatic diamines have a tendency to provide a stiffer (i.e., having ahigher Mooney viscosity) product than aliphatic or cycloaliphaticdiamines.

Depending on their chemical structure, curing agents may be slow- orfast-reacting polyamines or polyols. As described in U.S. Pat. Nos.6,793,864, 6,719,646 and copending U.S. Patent Publication No.2004/0201133 A1, (the contents of all of which are hereby incorporatedherein by reference), slow-reacting polyamines are diamines having aminegroups that are sterically and/or electronically hindered by electronwithdrawing groups or bulky groups situated proximate to the aminereaction sites. The spacing of the amine reaction sites will also affectthe reactivity speed of the polyamines.

Suitable curatives for use in the present invention are selected fromthe slow-reacting polyamine group include, but are not limited to,3,5-dimethylthio-2,4-toluenediamine;3,5-dimethylthio-2,6-toluenediamine; N,N′-dialkyldiamino diphenylmethane; trimethylene-glycol-di-p-aminobenzoate;polytetramethyleneoxide-di-p-aminobenzoate, and mixtures thereof. Ofthese, 3,5-dimethylthio-2,4-toluenediamine and3,5-dimethylthio-2,6-toluenediamine are isomers and are sold under thetrade name ETHACURE® 300 by Ethyl Corporation. Trimethyleneglycol-di-p-aminobenzoate is sold under the trade name POLACURE 740M andpolytetramethyleneoxide-di-p-aminobenzoates are sold under the tradename POLAMINES by Polaroid Corporation. N,N′-dialkyldiamino diphenylmethane is sold under the trade name UNILINK® by UOP.

When slow-reacting polyamines are used as the curing agent to produceurethane elastomers, a catalyst is typically needed to promote thereaction between the urethane prepolymer and the curing agent. Specificsuitable catalysts include TEDA (1) dissolved in di-propylene glycol(such as TEDA L33 available from Witco Corp. Greenwich, Conn., and DABCO33 LV available from Air Products and Chemicals Inc.). Catalysts areadded at suitable effective amounts, such as from about 2% to about 5%,and (2) more preferably TEDA dissolved in 1,4-butane diol from about 2%to about 5%. Another suitable catalyst includes a blend of 0.5% 33LV orTEDA L33 (above) with 0.1% dibutyl tin dilaurate (available from WitcoCorp. or Air Products and Chemicals, Inc.) which is added to a curativesuch as VIBRACURE® A250. Unfortunately, as is well known in the art, theuse of a catalyst can have a significant effect on the ability tocontrol the reaction and thus, on the overall processability.

To eliminate the need for a catalyst, a fast-reacting curing agent, oragents, can be used that does not have electron withdrawing groups orbulky groups that interfere with the reaction groups. However, theproblem with lack of control associated with the use of catalysts is notcompletely eliminated since fast-reacting curing agents also arerelatively difficult to control.

Preferred curing agent blends include using dicyandiamide in combinationwith fast curing agents such as diethyl-2,4-toluenediamine,4,4″-methylenebis-(3-chloro,2,6-diethyl)-aniline (available from AirProducts and Chemicals Inc., of Allentown, Pa., under the trade nameLONZACURE®), 3,3′-dichlorobenzidene; 3,3′-dichloro-4,4′-diaminodiphenylmethane (MOCA); N,N,N′,N′-tetrakis(2-hydroxypropyl) ethylenediamine andCuralon L, a trade name for a mixture of aromatic diamines sold byUniroyal, Inc. or any and all combinations thereof. A preferredfast-reacting curing agent is diethyl-2,4-toluene diamine, which has twocommercial grades names, Ethacure® 100 and Ethacure® 100LC commercialgrade has lower color and less by-product. In other words, it isconsidered a cleaner product to those skilled in the art.

Advantageously, the use of the Ethacure® 100LC commercial grade resultsin a golf ball that is less susceptible to yellowing when exposed to UVlight conditions. A player appreciates this desirable aesthetic effectalthough it should be noted that the instant invention may use either ofthese two commercial grades for the curing agentdiethyl-2,4-toluenediamine.

If a reduced-yellowing post curable composition is required, the chainextender or curing agent can further comprise a peroxide or peroxidemixture. Before the composition is exposed to sufficient thermal energyto reach the activation temperature of the peroxide, the composition of(a) and (b) behaves as a thermoplastic material. Therefore, it canreadily be formed into golf ball layers using injection molding.However, when sufficient thermal energy is applied to bring thecomposition above the peroxide activation temperature, crosslinkingoccurs, and the thermoplastic polyurethane is converted into crosslinkedpolyurethane.

Examples of suitable peroxides for use in compositions within the scopeof the present invention include aliphatic peroxides, aromaticperoxides, cyclic peroxides, or mixtures of these. Primary, secondary,or tertiary peroxides can be used, with tertiary peroxides mostpreferred. Also, peroxides containing more than one peroxy group can beused, such as 2,5-bis-(tert-butylperoxy)-2,5-dimethyl hexane and1,4-bis-(tert-butylperoxy-isopropyl)-benzene. Also, peroxides that areeither symmetrical or asymmetric can be used, such astert-butylperbenzoate and tert-butylcumylperoxide. Additionally,peroxides having carboxy groups also can be used. Decomposition ofperoxides used in compositions within the scope of the present inventioncan be brought about by applying thermal energy, shear, reactions withother chemical ingredients, or a combination of these. Homolyticallydecomposed peroxide, heterolytically decomposed peroxide, or a mixtureof those can be used to promote crosslinking reactions in compositionswithin the scope of this invention. Examples of suitable aliphaticperoxides and aromatic peroxides include diacetylperoxide,di-tert-butylperoxide, dibenzoylperoxide, dicumylperoxide,2,5-bis-(t-butylperoxy)-2,5-dimethyl hexane,2,5-dimethyl-2,5-di(benzoylperoxy)hexane,2,5-dimethyl-2,5-di(butylperoxy)-3-hexyne,n-butyl-4,4-bis(t-butylperoxyl) valerate,1,4-bis-(t-butylperoxyisopropyl)-benzene, t-butyl peroxybenzoate,1,1-bis-(t-butylperoxy)-3,3,5 tri-methylcyclohexane, anddi(2,4-dichloro-benzoyl). Peroxides for use within the scope of thisinvention may be acquired from Akzo Nobel Polymer Chemicals of Chicago,Ill., Atofina of Philadelphia, Pa. and Akrochem of Akron, Ohio. Furtherdetails of this post curable system are disclosed in U.S. Pat. No.6,924,337, the entire contents of which are hereby incorporated byreference.

The core and/or one or more mantle layers may comprise one or moreionomer resins. One family of such resins was developed in themid-1960's, by E.I. DuPont de Nemours and Co., and sold under thetrademark SURLYN®. Preparation of such ionomers is well known, forexample see U.S. Pat. No. 3,264,272. Generally speaking, most commercialionomers are unimodal and consist of a polymer of a mono-olefin, e.g.,an alkene, with an unsaturated mono- or dicarboxylic acids having 3 to12 carbon atoms. An additional monomer in the form of a mono- ordicarboxylic acid ester may also be incorporated in the formulation as aso-called “softening comonomer”. The incorporated carboxylic acid groupsare then neutralized by a basic metal ion salt, to form the ionomer. Themetal cations of the basic metal ion salt used for neutralizationinclude Li⁺, Na⁺, K⁺, Zn²⁺, Ca²⁺, Co²⁺, Ni²⁺, Cu²⁺, Pb²⁺, and Mg²⁺, withthe Li⁺, Na⁺, Ca²⁺, Zn²⁺, and Mg²⁺ being preferred. The basic metal ionsalts include those of for example formic acid, acetic acid, nitricacid, and carbonic acid, hydrogen carbonate salts, oxides, hydroxides,and alkoxides.

The first commercially available ionomer resins contained up to 16weight percent acrylic or methacrylic acid, although it was also wellknown at that time that, as a general rule, the hardness of these covermaterials could be increased with increasing acid content. Hence, inResearch Disclosure 29703, published in January 1989, DuPont disclosedionomers based on ethylene/acrylic acid or ethylene/methacrylic acidcontaining acid contents of greater than 15 weight percent. In this samedisclosure, DuPont also taught that such so called “high acid ionomers”had significantly improved stiffness and hardness and thus could beadvantageously used in golf ball construction, when used either singlyor in a blend with other ionomers.

More recently, high acid ionomers can be ionomer resins with acrylic ormethacrylic acid units present from 16 wt. % to about 35 wt. % in thepolymer. Generally, such a high acid ionomer will have a flexuralmodulus from about 50,000 psi to about 125,000 psi.

Ionomer resins further comprising a softening comonomer, present fromabout 10 wt. % to about 50 wt. % in the polymer, have a flexural modulusfrom about 2,000 psi to about 10,000 psi, and are sometimes referred toas “soft” or “very low modulus” ionomers. Typical softening comonomersinclude n-butyl acrylate, iso-butyl acrylate, n-butyl methacrylate,methyl acrylate and methyl methacrylate.

Today, there are a wide variety of commercially available ionomer resinsbased both on copolymers of ethylene and (meth)acrylic acid orterpolymers of ethylene and (meth)acrylic acid and (meth)acrylate, allof which can be used as a golf ball component. The properties of theseionomer resins can vary widely due to variations in acid content,softening comonomer content, the degree of neutralization, and the typeof metal ion used in the neutralization. The full range commerciallyavailable typically includes ionomers of polymers of general formula,E/X/Y polymer, wherein E is ethylene, X is a C₃ to C₈ α,β ethylenicallyunsaturated carboxylic acid, such as acrylic or methacrylic acid, and ispresent in an amount from about 0 wt. % to about 50 wt. %, particularlyabout 2 to about 30 weight %, of the E/X/Y copolymer, and Y is asoftening comonomer selected from the group consisting of alkyl acrylateand alkyl methacrylate, such as methyl acrylate or methyl methacrylate,and wherein the alkyl groups have from 1-8 carbon atoms, Y is in therange of 0 to about 50 weight %, particularly about 5 wt. % to about 35wt. %, of the E/X/Y copolymer, and wherein the acid groups present insaid ionomeric polymer are partially (e.g., about 1% to about 90%)neutralized with a metal selected from the group consisting of lithium,sodium, potassium, magnesium, calcium, barium, lead, tin, zinc oraluminum, or a combination of such cations.

The ionomer may also be a so-called bimodal ionomer as described in U.S.Pat. No. 6,562,906 (the entire contents of which are herein incorporatedby reference). These ionomers are bimodal as they are prepared fromblends comprising polymers of different molecular weights. Specifically,they include bimodal polymer blend compositions comprising:

-   -   a) a high molecular weight component having weight average        molecular weight (M_(W)) of about 80,000 to about 500,000 and        comprising one or more ethylene/α, β-ethylenically unsaturated        C₃₋₈ carboxylic acid copolymers and/or one or more ethylene,        alkyl (meth)acrylate, (meth)acrylic acid terpolymers; said high        molecular weight component being partially neutralized with        metal ions selected from the group consisting of lithium,        sodium, zinc, calcium, magnesium, and a mixture of any these;        and    -   b) a low molecular weight component having a weight average        molecular weight (M_(W)) of about from about 2,000 to about        30,000 and comprising one or more ethylene/α, β-ethylenically        unsaturated C₃₋₈ carboxylic acid copolymers and/or one or more        ethylene, alkyl (meth)acrylate, (meth)acrylic acid terpolymers;        said low molecular weight component being partially neutralized        with metal ions selected from the group consisting of lithium,        sodium, zinc, calcium, magnesium, and a mixture of any these.

In addition to the unimodal and bimodal ionomers, also included are theso-called “modified ionomers” examples of which are described in U.S.Pat. Nos. 6,100,321, 6,329,458 and 6,616,552 and U.S. Patent PublicationNo. US 2003/0158312 A1, the entire contents of all of which are hereinincorporated by reference.

The modified unimodal ionomers may be prepared by mixing:

-   -   a) an ionomeric polymer comprising ethylene, from 5 to 25 weight        percent (meth)acrylic acid, and from 0 to 40 weight percent of a        (meth)acrylate monomer, said ionomeric polymer neutralized with        metal ions selected from the group consisting of lithium,        sodium, zinc, calcium, magnesium, and a mixture of any of these;        and    -   b) from about 5 to about 40 weight percent (based on the total        weight of said modified ionomeric polymer) of one or more fatty        acids or metal salts of said fatty acid, the metal selected from        the group consisting of calcium, sodium, zinc, potassium, and        lithium, barium and magnesium and the fatty acid preferably        being stearic acid.

The modified bimodal ionomers, which are ionomers derived from theearlier described bimodal ethylene/carboxylic acid polymers (asdescribed in U.S. Pat. No. 6,562,906, the entire contents of which areherein incorporated by reference), are prepared by mixing;

-   -   a) a high molecular weight component having weight average        molecular weight (M_(W)) of about 80,000 to about 500,000 and        comprising one or more ethylene/α, β-ethylenically unsaturated        C₃₋₈ carboxylic acid copolymers and/or one or more ethylene,        alkyl (meth)acrylate, (meth)acrylic acid terpolymers; said high        molecular weight component being partially neutralized with        metal ions selected from the group consisting of lithium,        sodium, zinc, calcium, potassium, magnesium, and a mixture of        any of these; and    -   b) a low molecular weight component having a weight average        molecular weight (M_(w)) of about from about 2,000 to about        30,000 and comprising one or more ethylene/α, β-ethylenically        unsaturated C₃₋₈ carboxylic acid copolymers and/or one or more        ethylene, alkyl (meth)acrylate, (meth)acrylic acid terpolymers;        said low molecular weight component being partially neutralized        with metal ions selected from the group consisting of lithium,        sodium, zinc, calcium, potassium, magnesium, and a mixture of        any of these; and    -   c) from about 5 to about 40 weight percent (based on the total        weight of said modified ionomeric polymer) of one or more fatty        acids or metal salts of said fatty acid, the metal selected from        the group consisting of calcium, sodium, zinc, potassium and        lithium, barium and magnesium and the fatty acid preferably        being stearic acid.

The fatty or waxy acid salts utilized in the various modified ionomersare composed of a chain of alkyl groups containing from about 4 to 75carbon atoms (usually even numbered) and characterized by a —COOHterminal group. The generic formula for all fatty and waxy acids aboveacetic acid is CH₃ (CH₂)_(X) COOH, wherein the carbon atom countincludes the carboxyl group. The fatty or waxy acids utilized to producethe fatty or waxy acid salts modifiers may be saturated or unsaturated,and they may be present in solid, semi-solid or liquid form.

Examples of suitable saturated fatty acids, i.e., fatty acids in whichthe carbon atoms of the alkyl chain are connected by single bonds,include but are not limited to stearic acid (C₁₈, i.e., CH₃ (CH₂)₁₆COOH), palmitic acid (C₁₆, i.e., CH₃ (CH₂)₁₄ COOH), pelargonic acid (C₉,i.e., CH₃ (CH₂)₇ COOH) and lauric acid (C₁₂, i.e., CH₃ (CH₂)₁₀ OCOOH).Examples of suitable unsaturated fatty acids, i.e., a fatty acid inwhich there are one or more double bonds between the carbon atoms in thealkyl chain, include but are not limited to oleic acid (C₁₃, i.e., CH₃(CH₂)₇ CH:CH(CH₂)₇ COOH).

The source of the metal ions used to produce the metal salts of thefatty or waxy acid salts used in the various modified ionomers aregenerally various metal salts which provide the metal ions capable ofneutralizing, to various extents, the carboxylic acid groups of thefatty acids. These include the sulfate, carbonate, acetate andhydroxylate salts of zinc, barium, calcium and magnesium.

Since the fatty acid salts modifiers comprise various combinations offatty acids neutralized with a large number of different metal ions,several different types of fatty acid salts may be utilized in theinvention, including metal stearates, laureates, oleates, andpalmitates, with calcium, zinc, sodium, lithium, potassium and magnesiumstearate being preferred, and calcium and sodium stearate being mostpreferred.

The fatty or waxy acid or metal salt of said fatty or waxy acid ispresent in the modified ionomeric polymers in an amount of from about 5to about 40, preferably from about 7 to about 35, more preferably fromabout 8 to about 20 weight percent (based on the total weight of saidmodified ionomeric polymer).

As a result of the addition of the one or more metal salts of a fatty orwaxy acid, from about 40 to 100, preferably from about 50 to 100, morepreferably from about 70 to 100 percent of the acidic groups in thefinal modified ionomeric polymer composition are neutralized by a metalion.

An example of such a modified ionomer polymer is DuPont® HPF-1000available from E. I. DuPont de Nemours and Co. Inc.

A preferred ionomer composition may be prepared by blending one or moreof the unimodal ionomers, bimodal ionomers, or modified unimodal orbimodal ionomeric polymers as described herein, and further blended witha zinc neutralized ionomer of a polymer of general formula E/X/Y where Eis ethylene, X is a softening comonomer such as acrylate or methacrylateand is present in an amount of from 0 to about 50, preferably 0 to about25, most preferably 0, and Y is acrylic or methacrylic acid and ispresent in an amount from about 5 wt. % to about 25, preferably fromabout 10 to about 25, and most preferably about 10 to about 20 wt. % ofthe total composition.

In particular embodiment, blends used to make the core, intermediateand/or cover layers may include about 5 to about 95 wt. %, particularlyabout 5 to about 75 wt. %, preferably about 5 to about 55 wt. %, of aspecialty propylene elastomer(s) and about 95 to about 5 wt. %,particularly about 95 to about 25 wt. %, preferably about 95 to about 45wt. %, of at least one ionomer, especially a high-acid ionomer.

In yet another embodiment, a blend of an ionomer and a block copolymercan be included in the composition. An example of a block copolymer is afunctionalized styrenic block copolymer, the block copolymerincorporating a first polymer block having an aromatic vinyl compound, asecond polymer block having a conjugated diene compound, and a hydroxylgroup located at a block copolymer, or its hydrogenation product, inwhich the ratio of block copolymer to ionomer ranges from 5:95 to 95:5by weight, more preferably from about 10:90 to about 90:10 by weight,more preferably from about 20:80 to about 80:20 by weight, morepreferably from about 30:70 to about 70:30 by weight and most preferablyfrom about 35:65 to about 65:35 by weight. A preferred block copolymeris SEPTON HG-252. Such blends are described in more detail incommonly-assigned U.S. Pat. No. 6,861,474 and U.S. Patent PublicationNo. 2003/0224871 both of which are incorporated herein by reference intheir entireties.

In a further embodiment, the core, mantle and/or cover layers (andparticularly a mantle layer) can comprise a composition prepared byblending together at least three materials, identified as Components A,B, and C, and melt-processing these components to form in-situ a polymerblend composition incorporating a pseudo-crosslinked polymer network.Such blends are described in more detail in commonly-assigned U.S. Pat.No. 6,930,150, which is incorporated by reference herein in itsentirety. Component A is a monomer, oligomer, prepolymer or polymer thatincorporates at least five percent by weight of at least one type of ananionic functional group, and more preferably between about 5% and 50%by weight. Component B is a monomer, oligomer, or polymer thatincorporates less by weight of anionic functional groups than doesComponent A, Component B preferably incorporates less than about 25% byweight of anionic functional groups, more preferably less than about 20%by weight, more preferably less than about 10% by weight, and mostpreferably Component B is free of anionic functional groups. Component Cincorporates a metal cation, preferably as a metal salt. Thepseudo-crosslinked network structure is formed in-situ, not by covalentbonds, but instead by ionic clustering of the reacted functional groupsof Component A. The method can incorporate blending together more thanone of any of Components A, B, or C.

The polymer blend can include either Component A or B dispersed in aphase of the other. Preferably, blend compositions comprises betweenabout 1% and about 99% by weight of Component A based on the combinedweight of Components A and B, more preferably between about 10% andabout 90%, more preferably between about 20% and about 80%, and mostpreferably, between about 30% and about 70%. Component C is present in aquantity sufficient to produce the preferred amount of reaction of theanionic functional groups of Component A after sufficientmelt-processing. Preferably, after melt-processing at least about 5% ofthe anionic functional groups in the chemical structure of Component Ahave been consumed, more preferably between about 10% and about 90%,more preferably between about 10% and about 80%, and most preferablybetween about 10% and about 70%.

The composition preferably is prepared by mixing the above materialsinto each other thoroughly, either by using a dispersive mixingmechanism, a distributive mixing mechanism, or a combination of these.These mixing methods are well known in the manufacture of polymerblends. As a result of this mixing, the anionic functional group ofComponent A is dispersed evenly throughout the mixture. Next, reactionis made to take place in-situ at the site of the anionic functionalgroups of Component A with Component C in the presence of Component B.This reaction is prompted by addition of heat to the mixture. Thereaction results in the formation of ionic clusters in Component A andformation of a pseudo-crosslinked structure of Component A in thepresence of Component B. Depending upon the structure of Component B,this pseudo-crosslinked Component A can combine with Component B to forma variety of interpenetrating network structures. For example, thematerials can form a pseudo-crosslinked network of Component A dispersedin the phase of Component B, or Component B can be dispersed in thephase of the pseudo-crosslinked network of Component A. Component B mayor may not also form a network, depending upon its structure, resultingin either: a fully-interpenetrating network, i.e., two independentnetworks of Components A and B penetrating each other, but notcovalently bonded to each other; or, a semi-interpenetrating network ofComponents A and B, in which Component B forms a linear, grafted, orbranched polymer interspersed in the network of Component A. Forexample, a reactive functional group or an unsaturation in Component Bcan be reacted to form a crosslinked structure in the presence of thein-situ-formed, pseudo-crosslinked structure of Component A, leading toformation of a fully-interpenetrating network. Any anionic functionalgroups in Component B also can be reacted with the metal cation ofComponent C, resulting in pseudo-crosslinking via ionic clusterattraction of Component A to Component B.

The level of in-situ-formed pseudo-crosslinking in the compositionsformed by the present methods can be controlled as desired by selectionand ratio of Components A and B, amount and type of anionic functionalgroup, amount and type of metal cation in Component C, type and degreeof chemical reaction in Component B, and degree of pseudo-crosslinkingproduced of Components A and B.

As discussed above, the mechanical and thermal properties of the polymerblend for the inner mantle layer and/or the outer mantle layer can becontrolled as required by a modifying any of a number of factors,including: chemical structure of Components A and B, particularly theamount and type of anionic functional groups; mean molecular weight andmolecular weight distribution of Components A and B; linearity andcrystallinity of Components A and B; type of metal cation in ComponentC; degree of reaction achieved between the anionic functional groups andthe metal cation; mix ratio of Component A to Component B; type anddegree of chemical reaction in Component B; presence of chemicalreaction, such as a crosslinking reaction, between Components A and B;and the particular mixing methods and conditions used.

As discussed above, Component A can be any monomer, oligomer,prepolymer, or polymer incorporating at least 5% by weight of anionicfunctional groups. Those anionic functional groups can be incorporatedinto monomeric, oligomeric, prepolymeric, or polymeric structures duringthe synthesis of Component A, or they can be incorporated into apre-existing monomer, oligomer, prepolymer, or polymer throughsulfonation, phosphonation, or carboxylation to produce Component A.

Preferred, but non-limiting, examples of suitable copolymers andterpolymers include copolymers or terpolymers of: ethylene/acrylic acid,ethylene/methacrylic acid, ethylene/itaconic acid, ethylene/methylhydrogen maleate, ethylene/maleic acid, ethylene/methacrylicacid/ethylacrylate, ethylene/itaconic acid/methyl methacrylate,ethylene/methyl hydrogen maleate/ethyl acrylate, ethylene/methacrylicacid/vinyl acetate, ethylene/acrylic acid/vinyl alcohol,ethylene/propylene/acrylic acid, ethylene/styrene/acrylic acid,ethylene/methacrylic acid/acrylonitrile, ethylene/fumaric acid/vinylmethyl ether, ethylene/vinyl chloride/acrylic acid, ethylene/vinyldienechloride/acrylic acid, ethylene/vinyl fluoride/methacrylic acid, andethylene/chlorotrifluoroethylene/methacrylic acid, or anymetallocene-catalyzed polymers of the above-listed species.

Another family of thermoplastic elastomers for use in the golf balls arepolymers of i) ethylene and/or an alpha olefin; and ii) an α,β-ethylenically unsaturated C₃-C₂₀ carboxylic acid or anhydride, or anα, β-ethylenically unsaturated C₃-C₂₀ sulfonic acid or anhydride or anα, β-ethylenically unsaturated C₃-C₂₀ phosphoric acid or anhydride and,optionally iii) a C₁-C₁₀ ester of an α, β-ethylenically unsaturatedC₃-C₂₀ carboxylic acid or a C₁-C₁₀ ester of an α, β-ethylenicallyunsaturated C₃-C₂₀ sulfonic acid or a C₁-C₁₀ ester of an α,β-ethylenically unsaturated C₃-C₂₀ phosphoric acid.

Preferably, the alpha-olefin has from 2 to 10 carbon atoms and ispreferably ethylene, and the unsaturated carboxylic acid is a carboxylicacid having from about 3 to 8 carbons. Examples of such acids includeacrylic acid, methacrylic acid, ethacrylic acid, chloroacrylic acid,crotonic acid, maleic acid, fumaric acid, and itaconic acid, withacrylic acid being preferred. Preferably, the carboxylic acid ester ifpresent may be selected from the group consisting of vinyl esters ofaliphatic carboxylic acids wherein the acids have 2 to 10 carbon atomsand vinyl ethers wherein the alkyl groups contain 1 to 10 carbon atoms.

Examples of such polymers suitable for use include, but are not limitedto, an ethylene/acrylic acid copolymer, an ethylene/methacrylic acidcopolymer, an ethylene/itaconic acid copolymer, an ethylene/maleic acidcopolymer, an ethylene/methacrylic acid/vinyl acetate copolymer, anethylene/acrylic acid/vinyl alcohol copolymer, and the like.

Most preferred are ethylene/(meth)acrylic acid copolymers andethylene/(meth)acrylic acid/alkyl (meth)acrylate terpolymers, orethylene and/or propylene maleic anhydride copolymers and terpolymers.

The acid content of the polymer may contain anywhere from 1 to 30percent by weight acid. In some instances, it is preferable to utilize ahigh acid copolymer (i.e., a copolymer containing greater than 16% byweight acid, preferably from about 17 to about 25 weight percent acid,and more preferably about 20 weight percent acid).

Examples of such polymers which are commercially available include, butare not limited to, the Escor® 5000, 5001, 5020, 5050, 5070, 5100, 5110and 5200 series of ethylene-acrylic acid copolymers sold by Exxon andthe PRIMACOR® 1321, 1410, 1410-XT, 1420, 1430, 2912, 3150, 3330, 3340,3440, 3460, 4311, 4608 and 5980 series of ethylene-acrylic acidcopolymers sold by The Dow Chemical Company, Midland, Mich.

Also included are the bimodal ethylene/carboxylic acid polymers asdescribed in U.S. Pat. No. 6,562,906. These polymers compriseethylene/α, β-ethylenically unsaturated C₃₋₈ carboxylic acid highcopolymers, particularly ethylene (meth)acrylic acid copolymers andethylene, alkyl (meth)acrylate, (meth)acrylic acid terpolymers, havingmolecular weights of about 80,000 to about 500,000 which are meltblended with ethylene/α, β-ethylenically unsaturated C₃₋₈ carboxylicacid copolymers, particularly ethylene/(meth)acrylic acid copolymershaving molecular weights of about 2,000 to about 30,000.

As discussed above, Component B can be any monomer, oligomer, orpolymer, preferably having a lower weight percentage of anionicfunctional groups than that present in Component A in the weight rangesdiscussed above, and most preferably free of such functional groups.Examples of suitable materials for Component B include, but are notlimited to, the following: thermoplastic elastomer, thermoset elastomer,synthetic rubber, thermoplastic vulcanizate, copolymeric ionomer,terpolymeric ionomer, polycarbonate, polyolefin, polyamide, copolymericpolyamide, polyesters, polyvinyl alcohols,acrylonitrile-butadiene-styrene copolymers, polyurethane, polyarylate,polyacrylate, polyphenyl ether, modified-polyphenyl ether, high-impactpolystyrene, diallyl phthalate polymer, metallocene catalyzed polymers,acrylonitrile-styrene-butadiene (ABS), styrene-acrylonitrile (SAN)(including olefin-modified SAN and acrylonitrile styrene acrylonitrile),styrene-maleic anhydride (S/MA) polymer, styrenic copolymer,functionalized styrenic copolymer, functionalized styrenic terpolymer,styrenic terpolymer, cellulose polymer, liquid crystal polymer (LCP),ethylene-propylene-diene terpolymer (EPDM), ethylene-propylenecopolymer, ethylene vinyl acetate, polyurea, and polysiloxane or anymetallocene-catalyzed polymers of these species. Particularly suitablepolymers for use as Component B include polyethylene-terephthalate,polybutyleneterephthalate, polytrimethylene-terephthalate,ethylene-carbon monoxide copolymer, polyvinyl-diene fluorides,polyphenylenesulfide, polypropyleneoxide, polyphenyloxide,polypropylene, functionalized polypropylene, polyethylene,ethylene-octene copolymer, ethylene-methyl acrylate, ethylene-butylacrylate, polycarbonate, polysiloxane, functionalized polysiloxane,copolymeric ionomer, terpolymeric ionomer, polyetherester elastomer,polyesterester elastomer, polyetheramide elastomer, propylene-butadienecopolymer, modified copolymer of ethylene and propylene, styreniccopolymer (including styrenic block copolymer and randomly distributedstyrenic copolymer, such as styrene-isobutylene copolymer andstyrene-butadiene copolymer), partially or fully hydrogenatedstyrene-butadiene-styrene block copolymers such asstyrene-(ethylene-propylene)-styrene orstyrene-(ethylene-butylene)-styrene block copolymers, partially or fullyhydrogenated styrene-butadiene-styrene block copolymers with functionalgroup, polymers based on ethylene-propylene-(diene), polymers based onfunctionalized ethylene-propylene-diene), dynamically vulcanizedpolypropylene/ethylene-propylene-diene-copolymer, thermoplasticvulcanizates based on ethylene-propylene-(diene), thermoplasticpolyetherurethane, thermoplastic polyesterurethane, compositions formaking thermoset polyurethane, thermoset polyurethane, natural rubber,styrene-butadiene rubber, nitrile rubber, chloroprene rubber,fluorocarbon rubber, butyl rubber, acrylic rubber, silicone rubber,chlorosulfonated polyethylene, polyisobutylene, alfin rubber, polyesterrubber, epichlorohydrin rubber, chlorinated isobutylene-isoprene rubber,nitrile-isobutylene rubber, 1,2-polybutadiene, 1,4-polybutadiene,cis-polyisoprene, trans-polyisoprene, and polybutylene-octene.

Preferred materials for use as Component B include polyester elastomersmarketed under the name PEBAX and LOTADER marketed by ATOFINA Chemicalsof Philadelphia, Pa.; HYTREL, FUSABOND, and NUCREL marketed by E.I.DuPont de Nemours & Co. of Wilmington, Del.; SKYPEL and SKYTHANE by S.K.Chemicals of Seoul, South Korea; SEPTON and HYBRAR marketed by KurarayCompany of Kurashiki, Japan; ESTHANE by Noveon; and KRATON marketed byKraton Polymers. A most preferred material for use as Component B isSEPTON HG-252.

As stated above, Component C is a metal cation. These metals are fromgroups IA, IB, IIA, IIB, IIIA, IIIB, IVA, IVB, VA, VB, VIA, VIB, VIIBand VIIIB of the periodic table. Examples of these metals includelithium, sodium, magnesium, aluminum, potassium, calcium, manganese,tungsten, titanium, iron, cobalt, nickel, hafnium, copper, zinc, barium,zirconium, and tin. Suitable metal compounds for use as a source ofComponent C are, for example, metal salts, preferably metal hydroxides,metal carbonates, or metal acetates. In addition to Components A, B, andC, other materials commonly used in polymer blend compositions, can beincorporated into compositions prepared using these methods, including:crosslinking agents, co-crosslinking agents, accelerators, activators,UV-active chemicals such as UV initiators, EB-active chemicals,colorants, UV stabilizers, optical brighteners, antioxidants, processingaids, mold release agents, foaming agents, and organic, inorganic ormetallic fillers or fibers, including fillers to adjust specificgravity.

Various known methods are suitable for preparation of polymer blends.For example, the three components can be premixed together in any typeof suitable mixer, such as a V-blender, tumbler mixer, or blade mixer.This premix then can be melt-processed using an internal mixer, such asBanbury mixer, roll-mill or combination of these, to produce a reactionproduct of the anionic functional groups of Component A by Component Cin the presence of Component B. Alternatively, the premix can bemelt-processed using an extruder, such as single screw, co-rotating twinscrew, or counter-rotating twin screw extruder, to produce the reactionproduct. The mixing methods discussed above can be used together tomelt-mix the three components to prepare the compositions of the presentinvention. Also, the components can be fed into an extrudersimultaneously or sequentially.

Most preferably, Components A and B are melt-mixed together withoutComponent C, with or without the premixing discussed above, to produce amelt-mixture of the two components. Then, Component C separately ismixed into the blend of Components A and B. This mixture is melt-mixedto produce the reaction product. This two-step mixing can be performedin a single process, such as, for example, an extrusion process using aproper barrel length or screw configuration, along with a multiplefeeding system. In this case, Components A and B can be fed into theextruder through a main hopper to be melted and well-mixed while flowingdownstream through the extruder. Then Component C can be fed into theextruder to react with the mixture of Components A and B between thefeeding port for Component C and the die head of the extruder. The finalpolymer composition then exits from the die. If desired, any extra stepsof melt-mixing can be added to either approach of the method of thepresent invention to provide for improved mixing or completion of thereaction between Components A and C. Also, additional componentsdiscussed above can be incorporated either into a premix, or at any ofthe melt-mixing stages. Alternatively, Components A, B, and C can bemelt-mixed simultaneously to form in-situ a pseudo-crosslinked structureof Component A in the presence of Component B, either as a fully orsemi-interpenetrating network.

Illustrative polyamides for use in the compositions/golf balls disclosedinclude those obtained by: (1) polycondensation of (a) a dicarboxylicacid, such as oxalic acid, adipic acid, sebacic acid, terephthalic acid,isophthalic acid, or 1,4-cyclohexanedicarboxylic acid, with (b) adiamine, such as ethylenediamine, tetramethylenediamine,pentamethylenediamine, hexamethylenediamine, decamethylenediamine,1,4-cyclohexyldiamine or m-xylylenediamine; (2) a ring-openingpolymerization of cyclic lactam, such as ε-caprolactam or ω-laurolactam;(3) polycondensation of an aminocarboxylic acid, such as 6-aminocaproicacid, 9-aminononanoic acid, 11-aminoundecanoic acid or12-aminododecanoic acid; (4) copolymerization of a cyclic lactam with adicarboxylic acid and a diamine; or any combination of (1)-(4). Incertain examples, the dicarboxylic acid may be an aromatic dicarboxylicacid or a cycloaliphatic dicarboxylic acid. In certain examples, thediamine may be an aromatic diamine or a cycloaliphatic diamine. Specificexamples of suitable polyamides include polyamide 6; polyamide 11;polyamide 12; polyamide 4,6; polyamide 6,6; polyamide 6,9; polyamide6,10; polyamide 6,12; polyamide MXD6; PA12,CX; PA12, IT; PPA; PA6, IT;and PA6/PPE.

The polyamide may be any homopolyamide or copolyamide. One example of agroup of suitable polyamides is thermoplastic polyamide elastomers.Thermoplastic polyamide elastomers typically are copolymers of apolyamide and polyester or polyether. For example, the thermoplasticpolyamide elastomer can contain a polyamide (Nylon 6, Nylon 66, Nylon11, Nylon 12 and the like) as a hard segment and a polyether orpolyester as a soft segment. In one specific example, the thermoplasticpolyamides are amorphous copolyamides based on polyamide (PA 12).

One class of copolyamide elastomers are polyether amide elastomers.Illustrative examples of polyether amide elastomers are those thatresult from the copolycondensation of polyamide blocks having reactivechain ends with polyether blocks having reactive chain ends, including:

(1) polyamide blocks of diamine chain ends with polyoxyalkylenesequences of dicarboxylic chains;

(2) polyamide blocks of dicarboxylic chain ends with polyoxyalkylenesequences of diamine chain ends obtained by cyanoethylation andhydrogenation of polyoxyalkylene alpha-omega dihydroxylated aliphaticsequences known as polyether diols; and

(3) polyamide blocks of dicarboxylic chain ends with polyether diols,the products obtained, in this particular case, beingpolyetheresteramides.

More specifically, the polyamide elastomer can be prepared bypolycondensation of the components (i) a diamine and a dicarboxylate,lactames or an amino dicarboxylic acid (PA component), (ii) apolyoxyalkylene glycol such as polyoxyethylene glycol, polyoxy propyleneglycol (PG component) and (iii) a dicarboxylic acid.

The polyamide blocks of dicarboxylic chain ends come, for example, fromthe condensation of alpha-omega aminocarboxylic acids of lactam or ofcarboxylic diacids and diamines in the presence of a carboxylic diacidwhich limits the chain length. The molecular weight of the polyamidesequences is preferably between about 300 and 15,000, and morepreferably between about 600 and 5,000. The molecular weight of thepolyether sequences is preferably between about 100 and 6,000, and morepreferably between about 200 and 3,000.

The amide block polyethers may also comprise randomly distributed units.These polymers may be prepared by the simultaneous reaction of polyetherand precursor of polyamide blocks. For example, the polyether diol mayreact with a lactam (or alpha-omega amino acid) and a diacid whichlimits the chain in the presence of water. A polymer is obtained thathas primarily polyether blocks and/or polyamide blocks of very variablelength, but also the various reactive groups that have reacted in arandom manner and which are distributed statistically along the polymerchain.

Suitable amide block polyethers include those as disclosed in U.S. Pat.Nos. 4,331,786; 4,115,475; 4,195,015; 4,839,441; 4,864,014; 4,230,848and 4,332,920.

The polyether may be, for example, a polyethylene glycol (PEG), apolypropylene glycol (PPG), or a polytetramethylene glycol (PTMG), alsodesignated as polytetrahydrofurane (PTHF). The polyether blocks may bealong the polymer chain in the form of diols or diamines. However, forreasons of simplification, they are designated PEG blocks, or PPGblocks, or also PTMG blocks.

The polyether block comprises different units such as units which derivefrom ethylene glycol, propylene glycol, or tetramethylene glycol.

The amide block polyether comprises at least one type of polyamide blockand one type of polyether block. Mixing of two or more polymers withpolyamide blocks and polyether blocks may also be used. The amide blockpolyether also can comprise any amide structure made from the methoddescribed on the above.

Preferably, the amide block polyether is such that it represents themajor component in weight, i.e., that the amount of polyamide which isunder the block configuration and that which is eventually distributedstatistically in the chain represents 50 weight percent or more of theamide block polyether. Advantageously, the amount of polyamide and theamount of polyether is in a ratio (polyamide/polyether) of 1/1 to 3/1.

One type of polyetherester elastomer is the family of Pebax, which areavailable from Elf-Atochem Company. Preferably, the choice can be madefrom among Pebax 2533, 3533, 4033, 1205, 7033 and 7233. Blends orcombinations of Pebax 2533, 3533, 4033, 1205, 7033 and 7233 can also beprepared, as well. Pebax 2533 has a hardness of about 25 shore D(according to ASTM D-2240), a Flexural Modulus of 2.1 kpsi (according toASTM D-790), and a Bayshore resilience of about 62% (according to ASTMD-2632). Pebax 3533 has a hardness of about 35 shore D (according toASTM D-2240), a Flexural Modulus of 2.8 kpsi (according to ASTM D-790),and a Bayshore resilience of about 59% (according to ASTM D-2632). Pebax7033 has a hardness of about 69 shore D (according to ASTM D-2240) and aFlexural Modulus of 67 kpsi (according to ASTM D-790). Pebax 7333 has ahardness of about 72 shore D (according to ASTM D-2240) and a FlexuralModulus of 107 kpsi (according to ASTM D-790).

Some examples of suitable polyamides for use include those commerciallyavailable under the tradenames PEBAX, CRISTAMID and RILSAN marketed byAtofina Chemicals of Philadelphia, Pa., GRIVORY and GRILAMID marketed byEMS Chemie of Sumter, S.C., TROGAMID and VESTAMID available fromDegussa, and ZYTEL marketed by E.I. DuPont de Nemours & Co., ofWilmington, Del.

The layer or core compositions can also incorporate one or more fillers.Such fillers are typically in a finely divided form, for example, in asize generally less than about 20 mesh, preferably less than about 100mesh U.S. standard size, except for fibers and flock, which aregenerally elongated. Flock and fiber sizes should be small enough tofacilitate processing. Filler particle size will depend upon desiredeffect, cost, ease of addition, and dusting considerations. Theappropriate amounts of filler required will vary depending on theapplication but typically can be readily determined without undueexperimentation.

The filler preferably is selected from the group consisting ofprecipitated hydrated silica, limestone, clay, talc, asbestos, barytes,glass fibers, aramid fibers, mica, calcium metasilicate, barium sulfate,zinc sulfide, lithopone, silicates, silicon carbide, diatomaceous earth,carbonates such as calcium or magnesium or barium carbonate, sulfatessuch as calcium or magnesium or barium sulfate, metals, includingtungsten steel copper, cobalt or iron, metal alloys, tungsten carbide,metal oxides, metal stearates, and other particulate carbonaceousmaterials, and any and all combinations thereof. Preferred examples offillers include metal oxides, such as zinc oxide and magnesium oxide. Inanother preferred embodiment the filler comprises a continuous ornon-continuous fiber. In another preferred embodiment the fillercomprises one or more so called nanofillers, as described in U.S. Pat.No. 6,794,447 and U.S. Patent Publication No. 2004-0092336A1 publishedMay 13, 2004 and U.S. Patent Publication No. 2005-0059756A1 publishedMar. 17, 2005, the entire contents of each of which are hereinincorporated by reference.

Inorganic nanofiller material generally is made of clay, such ashydrotalcite, phyllosilicate, saponite, hectorite, beidellite,stevensite, vermiculite, halloysite, mica, montmorillonite,micafluoride, or octosilicate. To facilitate incorporation of thenanofiller material into a polymer material, either in preparingnanocomposite materials or in preparing polymer-based golf ballcompositions, the clay particles generally are coated or treated by asuitable compatibilizing agent. The compatibilizing agent allows forsuperior linkage between the inorganic and organic material, and it alsocan account for the hydrophilic nature of the inorganic nanofillermaterial and the possibly hydrophobic nature of the polymer.Compatibilizing agents may exhibit a variety of different structuresdepending upon the nature of both the inorganic nanofiller material andthe target matrix polymer. Non-limiting examples include hydroxy-,thiol-, amino-, epoxy-, carboxylic acid-, ester-, amide-, andsiloxy-group containing compounds, oligomers or polymers. The nanofillermaterials can be incorporated into the polymer either by dispersion intothe particular monomer or oligomer prior to polymerization, or by meltcompounding of the particles into the matrix polymer. Examples ofcommercial nanofillers are various Cloisite grades including 10A, 15A,20A, 25A, 30B, and NA+ of Southern Clay Products (Gonzales, Tex.) andthe Nanomer grades including 1.24TL and C.30EVA of Nanocor, Inc.(Arlington Heights, Ill.).

As mentioned above, the nanofiller particles have an aggregate structurewith the aggregates particle sizes in the micron range and above.However, these aggregates have a stacked plate structure with theindividual platelets being roughly 1 nanometer (nm) thick and 100 to1000 nm across. As a result, nanofillers have extremely high surfacearea, resulting in high reinforcement efficiency to the material at lowloading levels of the particles. The sub-micron-sized particles enhancethe stiffness of the material, without increasing its weight or opacityand without reducing the material's low-temperature toughness.

Nanofillers when added into a matrix polymer, can be mixed in threeways. In one type of mixing there is dispersion of the aggregatestructures within the matrix polymer, but on mixing no interaction ofthe matrix polymer with the aggregate platelet structure occurs, andthus the stacked platelet structure is essentially maintained. As usedherein, this type of mixing is defined as “undispersed”.

However, if the nanofiller material is selected correctly, the matrixpolymer chains can penetrate into the aggregates and separate theplatelets, and thus when viewed by transmission electron microscopy orx-ray diffraction, the aggregates of platelets are expanded. At thispoint the nanofiller is said to be substantially evenly dispersed withinand reacted into the structure of the matrix polymer. This level ofexpansion can occur to differing degrees. If small amounts of the matrixpolymer are layered between the individual platelets then, as usedherein, this type of mixing is known as “intercalation”.

In some cases, further penetration of the matrix polymer chains into theaggregate structure separates the platelets, and leads to a completebreaking up of the platelet's stacked structure in the aggregate andthus when viewed by transmission electron microscopy (TEM), theindividual platelets are thoroughly mixed throughout the matrix polymer.As used herein, this type of mixing is known as “exfoliated”. Anexfoliated nanofiller has the platelets fully dispersed throughout thepolymer matrix; the platelets may be dispersed unevenly but preferablyare dispersed evenly.

While not wishing to be limited to any theory, one possible explanationof the differing degrees of dispersion of such nanofillers within thematrix polymer structure is the effect of the compatibilizer surfacecoating on the interaction between the nanofiller platelet structure andthe matrix polymer. By careful selection of the nanofiller it ispossible to vary the penetration of the matrix polymer into the plateletstructure of the nanofiller on mixing. Thus, the degree of interactionand intrusion of the polymer matrix into the nanofiller controls theseparation and dispersion of the individual platelets of the nanofillerwithin the polymer matrix. This interaction of the polymer matrix andthe platelet structure of the nanofiller is defined herein as thenanofiller “reacting into the structure of the polymer” and thesubsequent dispersion of the platelets within the polymer matrix isdefined herein as the nanofiller “being substantially evenly dispersed”within the structure of the polymer matrix.

If no compatibilizer is present on the surface of a filler such as aclay, or if the coating of the clay is attempted after its addition tothe polymer matrix, then the penetration of the matrix polymer into thenanofiller is much less efficient, very little separation and nodispersion of the individual clay platelets occurs within the matrixpolymer.

As used herein, a “nanocomposite” is defined as a polymer matrix havingnanofiller intercalated or exfoliated within the matrix. Physicalproperties of the polymer will change with the addition of nanofillerand the physical properties of the polymer are expected to improve evenmore as the nanofiller is dispersed into the polymer matrix to form ananocomposite.

Materials incorporating nanofiller materials can provide these propertyimprovements at much lower densities than those incorporatingconventional fillers. For example, a nylon-6 nanocomposite materialmanufactured by RTP Corporation of Wichita, Kans. uses a 3% to 5% clayloading and has a tensile strength of 11,800 psi and a specific gravityof 1.14, while a conventional 30% mineral-filled material has a tensilestrength of 8,000 psi and a specific gravity of 1.36. Because use ofnanocomposite materials with lower loadings of inorganic materials thanconventional fillers provides the same properties, this use allowsproducts to be lighter than those with conventional fillers, whilemaintaining those same properties.

Nanocomposite materials are materials incorporating from about 0.1% toabout 20%, preferably from about 0.1% to about 15%, and most preferablyfrom about 0.1% to about 10% of nanofiller reacted into andsubstantially dispersed through intercalation or exfoliation into thestructure of an organic material, such as a polymer, to providestrength, temperature resistance, and other property improvements to theresulting composite. Descriptions of particular nanocomposite materialsand their manufacture can be found in U.S. Pat. No. 5,962,553 toEllsworth, U.S. Pat. No. 5,385,776 to Maxfield et al., and 4,894,411 toOkada et al. Examples of nanocomposite materials currently marketedinclude M1030D, manufactured by Unitika Limited, of Osaka, Japan, and1015C2, manufactured by UBE America of New York, N.Y.

When nanocomposites are blended with other polymer systems, thenanocomposite may be considered a type of nanofiller concentrate.However, a nanofiller concentrate may be more generally a polymer intowhich nanofiller is mixed; a nanofiller concentrate does not requirethat the nanofiller has reacted and/or dispersed evenly into the carrierpolymer.

Preferably the nanofiller material is added to the polymeric compositionin an amount of from about 0.1% to about 20%, preferably from about 0.1%to about 15%, and most preferably from about 0.1% to about 10% by weightof nanofiller reacted into and substantially dispersed throughintercalation or exfoliation into the structure of the polymericcomposition.

If desired, the various polymer compositions used to prepare the golfballs can additionally contain other additives such as plasticizers,pigments, antioxidants, U.V. absorbers, optical brighteners, or anyother additives generally employed in plastics formulation or thepreparation of golf balls.

Another particularly well-suited additive for use in the presentlydisclosed compositions includes compounds having the general formula:

(R₂N)_(m)—R′—(X(O)_(n)OR_(y))_(m),

where R is hydrogen, or a C₁-C₂₀ aliphatic, cycloaliphatic or aromaticsystems; R′ is a bridging group comprising one or more C₁-C₂₀ straightchain or branched aliphatic or alicyclic groups, or substituted straightchain or branched aliphatic or alicyclic groups, or aromatic group, oran oligomer of up to 12 repeating units including, but not limited to,polypeptides derived from an amino acid sequence of up to 12 aminoacids; and X is C or S or P with the proviso that when X═C, n=1 and y=1and when X═S, n=2 and y=1, and when X═P, n=2 and y=2. Also, m=1-3. Thesematerials are more fully described in copending U.S. Provisional PatentApplication No. 60/588,603, filed on Jul. 16, 2004, the entire contentsof which are herein incorporated by reference. These materials includecaprolactam, oenantholactam, decanolactam, undecanolactam,dodecanolactam, caproic 6-amino acid, 11-aminoundecanoicacid,12-aminododecanoic acid, diamine hexamethylene salts of adipic acid,azeleic acid, sebacic acid and 1,12-dodecanoic acid and the diaminenonamethylene salt of adipic acid., 2-aminocinnamic acid, L-asparticacid, 5-aminosalicylic acid, aminobutyric acid; aminocaproic acid;aminocapyryic acid; 1-(aminocarbonyl)-1-cyclopropanecarboxylic acid;aminocephalosporanic acid; aminobenzoic acid; aminochlorobenzoic acid;2-(3-amino-4-chlorobenzoyl)benzoic acid; aminonaphtoic acid;aminonicotinic acid; aminonorbornanecarboxylic acid; aminoorotic acid;aminopenicillanic acid; aminopentenoic acid; (aminophenyl)butyric acid;aminophenyl propionic acid; aminophthalic acid; aminofolic acid;aminopyrazine carboxylic acid; aminopyrazole carboxylic acid;aminosalicylic acid; aminoterephthalic acid; aminovaleric acid; ammoniumhydrogencitrate; anthranillic acid; aminobenzophenone carboxylic acid;aminosuccinamic acid, epsilon-caprolactam; omega-caprolactam,(carbamoylphenoxy)acetic acid, sodium salt; carbobenzyloxy asparticacid; carbobenzyl glutamine; carbobenzyloxyglycine; 2-aminoethylhydrogensulfate; aminonaphthalenesulfonic acid; aminotoluene sulfonicacid; 4,4′-methylene-bis-(cyclohexylamine)carbamate and ammoniumcarbamate.

Most preferably the material is selected from the group consisting of4,4′-methylene-bis-(cyclohexylamine)carbamate (commercially availablefrom R.T. Vanderbilt Co., Norwalk, Conn. under the tradename Diak® 4),11-aminoundecanoicacid, 12-aminododecanoic acid, epsilon-caprolactam;omega-caprolactam, and any and all combinations thereof.

In an especially preferred embodiment, a nanofiller additive componentin the golf ball is surface modified with a compatibilizing agentcomprising the earlier described compounds having the general formula:

(R₂N)_(m)—R′—(X(O)_(n)OR_(y))_(m),

A most preferred embodiment would be a filler comprising a nanofillerclay material surface modified with an amino acid including12-aminododecanoic acid. Such fillers are available from Nanonocor Co.under the tradename Nanomer 1.24TL.

Prior to its use in golf balls, the core and/or layer compositions maybe further formulated with one or more of the following blendcomponents:

Any crosslinking or curing system typically used for crosslinking may beused to crosslink the polymer(s), if desired. Satisfactory crosslinkingsystems are based on sulfur-, peroxide-, azide-, maleimide- orresin-vulcanization agents, which may be used in conjunction with avulcanization accelerator. Examples of satisfactory crosslinking systemcomponents are zinc oxide, sulfur, organic peroxide, azo compounds,magnesium oxide, benzothiazole sulfenamide accelerator, benzothiazyldisulfide, phenolic curing resin, m-phenylene bis-maleimide, thiuramdisulfide and dipentamethylene-thiuram hexasulfide.

More preferable cross-linking agents include peroxides, sulfurcompounds, as well as mixtures of these. Non-limiting examples ofsuitable cross-linking agents include primary, secondary, or tertiaryaliphatic or aromatic organic peroxides. Peroxides containing more thanone peroxy group can be used, such as2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and 1,4-di-(2-tert-butylperoxyisopropyl)benzene. Both symmetrical and asymmetrical peroxides canbe used, for example, tert-butyl perbenzoate and tert-butyl cumylperoxide. Peroxides incorporating carboxyl groups also are suitable. Thedecomposition of peroxides used as cross-linking agents in the disclosedcompositions can be brought about by applying thermal energy, shear,irradiation (e.g., ultraviolet-active agents or electron beam-activeagents), reaction with other chemicals, or any combination of these.Both homolytically and heterolytically decomposed peroxide can be used.Non-limiting examples of suitable peroxides include: diacetyl peroxide;di-tert-butyl peroxide; dibenzoyl peroxide; dicumyl peroxide;2,5-dimethyl-2,5-di(benzoylperoxy)hexane;1,4-bis-(t-butylperoxyisopropyl)benzene; t-butylperoxybenzoate;2,5-dimethyl-2,5-di-(t-butylperoxy)hexyne-3, such as Trigonox 145-45B,marketed by Akrochem Corp. of Akron, Ohio; 1,1-bis(t-butylperoxy)-3,3,5tri-methylcyclohexane, such as Varox 231-XL, marketed by R.T. VanderbiltCo., Inc. of Norwalk, Conn.; and di-(2,4-dichlorobenzoyl)peroxide.

The cross-linking agents can be blended in total amounts of about 0.01part to about 5 parts, more preferably about 0.05 part to about 4 parts,and most preferably about 0.1 part to about 2 parts, by weight of thecross-linking agents per 100 parts by weight of the polymer-containingcomposition.

In a further embodiment, the cross-linking agents can be blended intotal amounts of about 0.05 part to about 5 parts, more preferably about0.2 part to about 3 parts, and most preferably about 0.2 part to about 2parts, by weight of the cross-linking agents per 100 parts by weight ofthe polymer-containing composition.

Each peroxide cross-linking agent has a characteristic decompositiontemperature at which 50% of the cross-linking agent has decomposed whensubjected to that temperature for a specified time period (t_(1/2)). Forexample, 1,1-bis-(t-butylperoxy)-3,3,5-tri-methylcyclohexane att_(1/2)=0.1 hour has a decomposition temperature of 138° C. and2,5-dimethyl-2,5-di-(t-butylperoxy)hexyne-3 at t_(1/2)=0.1 hour has adecomposition temperature of 182° C. Two or more cross-linking agentshaving different characteristic decomposition temperatures at the samet_(1/2) may be blended in the composition. For example, where at leastone cross-linking agent has a first characteristic decompositiontemperature less than 150° C., and at least one cross-linking agent hasa second characteristic decomposition temperature greater than 150° C.,the composition weight ratio of the at least one cross-linking agenthaving the first characteristic decomposition temperature to the atleast one cross-linking agent having the second characteristicdecomposition temperature can range from 5:95 to 95:5, or morepreferably from 10:90 to 50:50.

Besides the use of chemical cross-linking agents, exposure of thepolymer-containing composition to radiation also can serve as across-linking agent. Radiation can be applied to the polymer-containingcomposition by any known method, including using microwave or gammaradiation, or an electron beam device. Additives may also be used toimprove radiation-induced crosslinking of the polymer-containingcomposition.

The polymer containing-composition may also be blended with aco-cross-linking agent, which may be a metal salt of an unsaturatedcarboxylic acid. Examples of these include zinc and magnesium salts ofunsaturated fatty acids having 3 to 8 carbon atoms, such as acrylicacid, methacrylic acid, maleic acid, and fumaric acid, palmitic acidwith the zinc salts of acrylic and methacrylic acid being mostpreferred. The unsaturated carboxylic acid metal salt can be blended inthe polymer-containing composition either as a preformed metal salt, orby introducing an α,ß-unsaturated carboxylic acid and a metal oxide orhydroxide into the polymer-containing composition, and allowing them toreact to form the metal salt. The unsaturated carboxylic acid metal saltcan be blended in any desired amount, but preferably in amounts of about1 part to about 100 parts by weight of the unsaturated carboxylic acidper 100 parts by weight of the polymer-containing composition.

The polymer-containing composition may also incorporate one or more ofthe so-called “peptizers”.

The peptizer preferably comprises an organic sulfur compound and/or itsmetal or non-metal salt. Examples of such organic sulfur compoundsinclude thiophenols, such as pentachlorothiophenol,4-butyl-o-thiocresol, 4 t-butyl-p-thiocresol, and 2-benzamidothiophenol;thiocarboxylic acids, such as thiobenzoic acid; 4,4′ dithiodimorpholine; and, sulfides, such as dixylyl disulfide, dibenzoyldisulfide; dibenzothiazyl disulfide; di(pentachlorophenyl) disulfide;dibenzamido diphenyldisulfide (DBDD), and alkylated phenol sulfides,such as VULTAC marketed by Atofina Chemicals, Inc. of Philadelphia, Pa.Preferred organic sulfur compounds include pentachlorothiophenol, anddibenzamido diphenyldisulfide.

Examples of the metal salt of an organic sulfur compound include sodium,potassium, lithium, magnesium calcium, barium, cesium and zinc salts ofthe above-mentioned thiophenols and thiocarboxylic acids, with the zincsalt of pentachlorothiophenol being most preferred.

Examples of the non-metal salt of an organic sulfur compound includeammonium salts of the above-mentioned thiophenols and thiocarboxylicacids wherein the ammonium cation has the general formula [NR¹R²R³R⁴]⁺where R¹, R², R³ and R⁴ are selected from the group consisting ofhydrogen, a C₁-C₂₀ aliphatic, cycloaliphatic or aromatic moiety, and anyand all combinations thereof, with the most preferred being the NH₄⁺-salt of pentachlorothiophenol.

Additional peptizers include aromatic or conjugated peptizers comprisingone or more heteroatoms, such as nitrogen, oxygen and/or sulfur. Moretypically, such peptizers are heteroaryl or heterocyclic compoundshaving at least one heteroatom, and potentially plural heteroatoms,where the plural heteroatoms may be the same or different. Suchpeptizers include peptizers such as an indole peptizer, a quinolinepeptizer, an isoquinoline peptizer, a pyridine peptizer, purinepeptizer, a pyrimidine peptizer, a diazine peptizer, a pyrazinepeptizer, a triazine peptizer, a carbazole peptizer, or combinations ofsuch peptizers.

Suitable peptizers also may include one or more additional functionalgroups, such as halogens, particularly chlorine; a sulfur-containingmoiety exemplified by thiols, where the functional group is sulfhydryl(—SH), thioethers, where the functional group is —SR, disulfides,(R₁S—SR₂₂), etc.; and combinations of functional groups. Such peptizersare more fully disclosed in copending U.S. Application No. 60/752,475filed on Dec. 20, 2005 in the name of Hyun Kim et al, the entirecontents of which are herein incorporated by reference. A most preferredexample is a pyridine peptizer that also includes a chlorine functionalgroup and a thiol functional group such as2,3,5,6-tetrachloro-4-pyridinethiol (TCPT).

The peptizer, if employed in the golf balls, is present in an amount offrom about 0.01 to about 10, preferably of from about 0.05 to about 7,more preferably of from about 0.1 to about 5 parts by weight per 100parts by weight of the polymer-containing composition.

The polymer-containing composition can also comprise one or moreaccelerators of one or more classes. Accelerators are added to anunsaturated polymer to increase the vulcanization rate and/or decreasethe vulcanization temperature. Accelerators can be of any class knownfor rubber processing including mercapto-, sulfenamide-, thiuram,dithiocarbamate, dithiocarbamyl-sulfenamide, xanthate, guanidine, amine,thiourea, and dithiophosphate accelerators. Specific commercialaccelerators include 2-mercaptobenzothiazole and its metal or non-metalsalts, such as Vulkacit Mercapto C, Mercapto MGC, Mercapto ZM-5, and ZMmarketed by Bayer AG of Leverkusen, Germany, Nocceler M, Nocceler MZ,and Nocceler M-60 marketed by Ouchisinko Chemical Industrial Company,Ltd. of Tokyo, Japan, and MBT and ZMBT marketed by Akrochem Corporationof Akron, Ohio. A more complete list of commercially availableaccelerators is given in The Vanderbilt Rubber Handbook: 13^(th) Edition(1990, R.T. Vanderbilt Co.), pp. 296-330, in Encyclopedia of PolymerScience and Technology, Vol. 12 (1970, John Wiley & Sons), pp. 258-259,and in Rubber Technology Handbook (1980, Hanser/Gardner Publications),pp. 234-236. Preferred accelerators include 2-mercaptobenzothiazole(MBT) and its salts.

The polymer-containing composition can further incorporate from about0.01 part to about 10 parts by weight of the accelerator per 100 partsby weight of the polymer-containing composition. More preferably, theball composition can further incorporate from about 0.02 part to about 5parts, and most preferably from about 0.03 part to about 1.5 parts, byweight of the accelerator per 100 parts by weight of the polymer.

The core may be made from any of the polymers described above. Incertain embodiments, the core is made from polybutadiene. In particularexamples, the polybutadiene is the “major ingredient” of the coremeaning that the polybutadiene constitutes at least 50, moreparticularly 60, most particularly 80, wt %, of all the ingredients inthe core. In further embodiments, polybutadiene is the only polymerpresent in the core.

The mantle layer(s) may be made from any suitable material, particularlythose materials described herein. In certain examples, the mantle layersmay include a unimodal ionomer; a bimodal ionomer; a modified unimodalionomer; a modified bimodal ionomer; a thermoset polyurethane; apolyester elastomer; a copolymer comprising at least one firstco-monomer selected from butadiene, isoprene, ethylene or butylene andat least one second co-monomer selected from a (meth)acrylate or a vinylarylene; a polyalkenamer; or any and all combinations or mixturesthereof. The above-listed mantle layer material(s) may be the “majoringredient” of the mantle layer meaning that the material(s) constitutesat least 50, more particularly 60, most particularly 80, wt %, of allthe ingredients in the mantle layer. In further embodiments, theabove-listed mantle layer material(s) is the only polymer(s) present inthe mantle layer(s).

The cover layer of the balls may have a thickness of about 0.01 to about0.10, preferably from about 0.02 to about 0.08, more preferably fromabout 0.03 to about 0.06 inch.

The cover layer of the balls may have a hardness Shore D from about 20to about 80, preferably from about 30 to about 75 or about 50 to about70, more preferably from 47 to about 68 or about 45 to about 70, andmost preferably from about 50 to about 65.

A coating layer may be disposed on, or adjacent to, the outer coverlayer. For example, the coating layer may be a thermoplastic resin-basedpaint and/or a thermosetting resin-based paint. Examples of such paintsinclude vinyl acetate resin paints, vinyl acetate copolymer resinpaints, EVA (ethylene-vinyl acetate copolymer resin) paints, acrylicester (co)polymer resin paints, epoxy resin paints, thermosettingurethane resin paints, thermoplastic urethane resin paints,thermosetting acrylic resin paints, and unsaturated polyester resinpaints. The coating layer may be transparent, semi-transparent,translucent, or matte.

In view of the many possible embodiments to which the principles of thedisclosed invention may be applied, it should be recognized that theillustrated embodiments are only preferred examples of the invention andshould not be taken as limiting the scope of the invention.

What is claimed is:
 1. A golf ball comprising: at least one core; and acover layer formed from a cast polyurethane or polyurea, wherein thecover layer defines a first surface area portion of a first color and asecond surface area portion of a single pass printed image, and a seamupon which the single pass printed image is placed, wherein the singlepass printed image is printed using a UV curable ink and at least one UVpinning operation to pre-cure the UV curable ink before a final UVcuring operation.
 2. The golf ball of claim 1, wherein a throw distanceutilized to print the single pass printed image is between 0 and 10 mm.3. The golf ball of claim 1, wherein an energy density of a UV pinninglamp in the UV pinning operation is between 50 mJ/cm² to 200 mJ/cm² andat least one final UV curing lamp used in the final UV curing operationis between 1 J/cm² and 5 J/cm².
 4. The golf ball of claim 1, wherein aresolution of the single pass printed image is between 100 dpi and 1400dpi.
 5. The golf ball of claim 1, wherein a print swathe of the singlepass printed image is between 1 mm and 25 mm.
 6. The golf ball of claim1, wherein a dispense rate or the velocity of the ink droplet to printthe single pass printed image is between 2 m/s and 10 m/s.
 7. The golfball of claim 1, wherein a volume of a single UV curable ink droplet isbetween 6 to 160 picoliters when printing the single pass printed image.8. The golf ball of claim 1, wherein the single pass printed image hasan upper zone of distortion.
 9. The golf ball of claim 1, wherein thesingle pass printed image has a lower zone of distortion.
 10. The golfball of claim 1, wherein the single pass printed image was printed whilethe ball was rotating at a rotation rate of between 1 rpm and 400 rpm.11. A golf ball comprising: at least one core; and a cover layer formedfrom a cast polyurethane or polyurea, wherein the cover layer defines afirst surface area portion of a first color and a second surface areaportion of at least one single pass printed image, and a first locationupon which the at least one single pass printed image is placed, whereinthe at least one single pass printed image is either rotationally orlinearly printed using a UV curable ink and at least one UV pinningoperation to pre-cure the UV curable ink before a final UV curingoperation; wherein a throw distance utilized to print the at least onesingle pass printed image on the cover layer is between 0 and 10 mm;wherein an energy density of a UV pinning lamp in the UV pinningoperation is between 50 mJ/cm² to 200 mJ/cm² and at least one final UVcuring lamp used in the final UV curing operation is between 1 J/cm² and5 J/cm²; wherein a resolution of the at least one single pass printedimage is between 100 dpi and 1400 dpi and a volume of a single inkdroplet is between 6 to 160 picoliters when printing the at least onesingle pass printed image.
 12. The golf ball of claim 11, wherein the atleast one single pass printed image has an upper zone of distortion. 13.The golf ball of claim 11, wherein the at least one single pass printedimage has a lower zone of distortion.
 14. The golf ball of claim 11,wherein the at least one single pass printed image was printed while theball was rotating at a rotation rate of between 1 rpm and 400 rpm. 15.The golf ball of claim 11, wherein a print swathe of the at least onesingle pass printed image is between 1 mm and 25 mm.
 16. The golf ballof claim 11, wherein the at least one single pass printed image wasprinted with a ratio of the printer resolution divided by a lineardirection speed of between 10 dpi/(inches/sec) and 100 dpi/(inches/sec).17. The golf ball of claim 11, wherein the at least one single passprinted image was printed with a ratio of the printer resolution dividedby a linear direction speed of between 20 dip/(inches/sec) and 50dpi/(inches/sec).
 18. The golf ball of claim 16, wherein the at leastone single pass printed image is two images located in two distinctareas on the cover layer of the golf ball.
 19. The golf ball of claim16, wherein the at least one single pass printed image is located in aregion of a seam of the golf ball.
 20. A method of manufacturingcomprising: providing at least one golf ball core; providing a coverlayer formed from a cast polyurethane or polyurea, wherein the coverlayer defines a first surface area portion of a first color and a secondsurface area portion having at least one single pass printed image;providing a first location on the cover layer upon which the at leastone single pass printed image is placed, wherein the at least one singlepass printed image is either rotationally or linearly printed using a UVcurable ink; providing at least one UV pinning operation to pre-cure theUV curable ink; providing a final UV curing operation to cure the UVcurable ink; providing a throw distance utilized to print the at leastone single pass printed image on the cover layer is between 0 and 10 mm;providing an energy density of a UV pinning lamp in the at least one UVpinning operation is between 50 mJ/cm² to 200 mJ/cm² and at least onefinal UV curing lamp used in the final UV curing operation is between 1J/cm² and 5 J/cm²; and wherein a resolution of the at least one singlepass printed image is between 100 dpi and 1400 dpi and a volume of asingle ink droplet is between 6 to 160 picoliters when printing the atleast one single pass printed image.
 21. A method comprising: singlepass printing at least one image onto a first location on a golf ballcover layer, wherein the at least one single pass printed image iseither rotationally or linearly printed using a UV curable ink, whereina throw distance of between 0 and 10 mm is utilized for the single passprinting of the at least one image, a resolution of the at least onesingle pass printed image is between 100 dpi and 1400 dpi and a volumeof a single UV curable ink droplet is between 6 to 160 picoliters whenprinting the at least one single pass printed image; subjecting the UVcurable ink to a UV pinning lamp having an energy density of between 50mJ/cm² to 200 mJ/cm², thereby pre-curing the UV curable ink; andsubjecting the pre-cured UV curable ink to a final UV curing lamp havingan energy density of between 1 J/cm² and 5 J/cm², thereby completingcuring the pre-cured UV curable ink.